2009-09-16 03:50:15 -06:00
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/*
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* Copyright (C) 2008, 2009 Intel Corporation
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* Authors: Andi Kleen, Fengguang Wu
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*
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* This software may be redistributed and/or modified under the terms of
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* the GNU General Public License ("GPL") version 2 only as published by the
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* Free Software Foundation.
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*
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* High level machine check handler. Handles pages reported by the
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2010-09-27 15:09:51 -06:00
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* hardware as being corrupted usually due to a multi-bit ECC memory or cache
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2009-09-16 03:50:15 -06:00
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* failure.
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2010-09-27 15:09:51 -06:00
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*
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* In addition there is a "soft offline" entry point that allows stop using
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* not-yet-corrupted-by-suspicious pages without killing anything.
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2009-09-16 03:50:15 -06:00
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*
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* Handles page cache pages in various states. The tricky part
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2010-09-27 15:09:51 -06:00
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* here is that we can access any page asynchronously in respect to
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* other VM users, because memory failures could happen anytime and
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* anywhere. This could violate some of their assumptions. This is why
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* this code has to be extremely careful. Generally it tries to use
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* normal locking rules, as in get the standard locks, even if that means
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* the error handling takes potentially a long time.
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2015-06-24 17:56:02 -06:00
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*
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* It can be very tempting to add handling for obscure cases here.
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* In general any code for handling new cases should only be added iff:
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* - You know how to test it.
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* - You have a test that can be added to mce-test
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* https://git.kernel.org/cgit/utils/cpu/mce/mce-test.git/
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* - The case actually shows up as a frequent (top 10) page state in
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* tools/vm/page-types when running a real workload.
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2010-09-27 15:09:51 -06:00
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*
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* There are several operations here with exponential complexity because
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* of unsuitable VM data structures. For example the operation to map back
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* from RMAP chains to processes has to walk the complete process list and
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* has non linear complexity with the number. But since memory corruptions
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* are rare we hope to get away with this. This avoids impacting the core
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* VM.
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2009-09-16 03:50:15 -06:00
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*/
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/page-flags.h>
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2009-12-16 04:19:59 -07:00
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#include <linux/kernel-page-flags.h>
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2017-02-08 10:51:30 -07:00
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#include <linux/sched/signal.h>
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2017-02-08 10:51:36 -07:00
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#include <linux/sched/task.h>
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2009-10-13 08:02:11 -06:00
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#include <linux/ksm.h>
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2009-09-16 03:50:15 -06:00
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#include <linux/rmap.h>
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2011-05-26 14:00:52 -06:00
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#include <linux/export.h>
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2009-09-16 03:50:15 -06:00
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#include <linux/pagemap.h>
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#include <linux/swap.h>
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#include <linux/backing-dev.h>
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2009-12-16 04:20:00 -07:00
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#include <linux/migrate.h>
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#include <linux/page-isolation.h>
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#include <linux/suspend.h>
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include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 02:04:11 -06:00
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#include <linux/slab.h>
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2010-05-31 00:28:19 -06:00
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#include <linux/swapops.h>
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2010-05-27 18:29:17 -06:00
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#include <linux/hugetlb.h>
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2010-12-02 15:31:19 -07:00
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#include <linux/memory_hotplug.h>
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2011-06-15 16:08:48 -06:00
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#include <linux/mm_inline.h>
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2011-07-12 23:14:27 -06:00
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#include <linux/kfifo.h>
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2015-11-05 19:47:26 -07:00
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#include <linux/ratelimit.h>
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2009-09-16 03:50:15 -06:00
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#include "internal.h"
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2015-06-24 17:57:36 -06:00
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#include "ras/ras_event.h"
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2009-09-16 03:50:15 -06:00
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int sysctl_memory_failure_early_kill __read_mostly = 0;
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int sysctl_memory_failure_recovery __read_mostly = 1;
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2013-02-22 17:34:02 -07:00
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atomic_long_t num_poisoned_pages __read_mostly = ATOMIC_LONG_INIT(0);
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2009-09-16 03:50:15 -06:00
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2009-12-21 11:56:42 -07:00
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#if defined(CONFIG_HWPOISON_INJECT) || defined(CONFIG_HWPOISON_INJECT_MODULE)
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2009-12-16 04:19:59 -07:00
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u32 hwpoison_filter_enable = 0;
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2009-12-16 04:19:59 -07:00
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u32 hwpoison_filter_dev_major = ~0U;
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u32 hwpoison_filter_dev_minor = ~0U;
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2009-12-16 04:19:59 -07:00
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u64 hwpoison_filter_flags_mask;
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u64 hwpoison_filter_flags_value;
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2009-12-16 04:19:59 -07:00
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EXPORT_SYMBOL_GPL(hwpoison_filter_enable);
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2009-12-16 04:19:59 -07:00
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EXPORT_SYMBOL_GPL(hwpoison_filter_dev_major);
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EXPORT_SYMBOL_GPL(hwpoison_filter_dev_minor);
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2009-12-16 04:19:59 -07:00
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EXPORT_SYMBOL_GPL(hwpoison_filter_flags_mask);
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EXPORT_SYMBOL_GPL(hwpoison_filter_flags_value);
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2009-12-16 04:19:59 -07:00
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static int hwpoison_filter_dev(struct page *p)
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{
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struct address_space *mapping;
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dev_t dev;
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if (hwpoison_filter_dev_major == ~0U &&
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hwpoison_filter_dev_minor == ~0U)
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return 0;
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/*
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2010-09-27 15:09:51 -06:00
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* page_mapping() does not accept slab pages.
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2009-12-16 04:19:59 -07:00
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*/
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if (PageSlab(p))
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return -EINVAL;
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mapping = page_mapping(p);
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if (mapping == NULL || mapping->host == NULL)
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return -EINVAL;
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dev = mapping->host->i_sb->s_dev;
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if (hwpoison_filter_dev_major != ~0U &&
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hwpoison_filter_dev_major != MAJOR(dev))
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return -EINVAL;
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if (hwpoison_filter_dev_minor != ~0U &&
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hwpoison_filter_dev_minor != MINOR(dev))
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return -EINVAL;
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return 0;
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}
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2009-12-16 04:19:59 -07:00
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static int hwpoison_filter_flags(struct page *p)
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{
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if (!hwpoison_filter_flags_mask)
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return 0;
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if ((stable_page_flags(p) & hwpoison_filter_flags_mask) ==
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hwpoison_filter_flags_value)
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return 0;
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else
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return -EINVAL;
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}
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2009-12-16 04:19:59 -07:00
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/*
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* This allows stress tests to limit test scope to a collection of tasks
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* by putting them under some memcg. This prevents killing unrelated/important
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* processes such as /sbin/init. Note that the target task may share clean
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* pages with init (eg. libc text), which is harmless. If the target task
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* share _dirty_ pages with another task B, the test scheme must make sure B
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* is also included in the memcg. At last, due to race conditions this filter
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* can only guarantee that the page either belongs to the memcg tasks, or is
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* a freed page.
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*/
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2015-09-09 16:35:31 -06:00
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#ifdef CONFIG_MEMCG
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2009-12-16 04:19:59 -07:00
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u64 hwpoison_filter_memcg;
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EXPORT_SYMBOL_GPL(hwpoison_filter_memcg);
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static int hwpoison_filter_task(struct page *p)
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{
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if (!hwpoison_filter_memcg)
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return 0;
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2015-09-09 16:35:31 -06:00
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if (page_cgroup_ino(p) != hwpoison_filter_memcg)
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2009-12-16 04:19:59 -07:00
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return -EINVAL;
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return 0;
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}
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#else
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static int hwpoison_filter_task(struct page *p) { return 0; }
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#endif
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2009-12-16 04:19:59 -07:00
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int hwpoison_filter(struct page *p)
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{
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2009-12-16 04:19:59 -07:00
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if (!hwpoison_filter_enable)
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return 0;
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2009-12-16 04:19:59 -07:00
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if (hwpoison_filter_dev(p))
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return -EINVAL;
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2009-12-16 04:19:59 -07:00
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if (hwpoison_filter_flags(p))
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return -EINVAL;
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2009-12-16 04:19:59 -07:00
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if (hwpoison_filter_task(p))
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return -EINVAL;
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2009-12-16 04:19:59 -07:00
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return 0;
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}
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2009-12-21 11:56:42 -07:00
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#else
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int hwpoison_filter(struct page *p)
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{
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return 0;
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}
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#endif
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2009-12-16 04:19:59 -07:00
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EXPORT_SYMBOL_GPL(hwpoison_filter);
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2009-09-16 03:50:15 -06:00
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/*
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2011-12-13 10:27:58 -07:00
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* Send all the processes who have the page mapped a signal.
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* ``action optional'' if they are not immediately affected by the error
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* ``action required'' if error happened in current execution context
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2009-09-16 03:50:15 -06:00
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*/
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2011-12-13 10:27:58 -07:00
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static int kill_proc(struct task_struct *t, unsigned long addr, int trapno,
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unsigned long pfn, struct page *page, int flags)
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2009-09-16 03:50:15 -06:00
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{
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struct siginfo si;
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int ret;
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2016-05-20 17:57:32 -06:00
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pr_err("Memory failure: %#lx: Killing %s:%d due to hardware memory corruption\n",
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pfn, t->comm, t->pid);
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2009-09-16 03:50:15 -06:00
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si.si_signo = SIGBUS;
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si.si_errno = 0;
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si.si_addr = (void *)addr;
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#ifdef __ARCH_SI_TRAPNO
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si.si_trapno = trapno;
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#endif
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2013-09-11 15:22:52 -06:00
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si.si_addr_lsb = compound_order(compound_head(page)) + PAGE_SHIFT;
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2011-12-13 10:27:58 -07:00
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2014-06-04 17:10:59 -06:00
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if ((flags & MF_ACTION_REQUIRED) && t->mm == current->mm) {
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2011-12-13 10:27:58 -07:00
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si.si_code = BUS_MCEERR_AR;
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2014-06-04 17:10:59 -06:00
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ret = force_sig_info(SIGBUS, &si, current);
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2011-12-13 10:27:58 -07:00
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} else {
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/*
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* Don't use force here, it's convenient if the signal
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* can be temporarily blocked.
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* This could cause a loop when the user sets SIGBUS
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* to SIG_IGN, but hopefully no one will do that?
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*/
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si.si_code = BUS_MCEERR_AO;
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ret = send_sig_info(SIGBUS, &si, t); /* synchronous? */
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}
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2009-09-16 03:50:15 -06:00
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if (ret < 0)
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2016-05-20 17:57:32 -06:00
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pr_info("Memory failure: Error sending signal to %s:%d: %d\n",
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2016-03-17 15:19:50 -06:00
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t->comm, t->pid, ret);
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2009-09-16 03:50:15 -06:00
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return ret;
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}
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2009-12-16 04:19:57 -07:00
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/*
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* When a unknown page type is encountered drain as many buffers as possible
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* in the hope to turn the page into a LRU or free page, which we can handle.
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*/
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2009-12-16 04:20:00 -07:00
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void shake_page(struct page *p, int access)
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2009-12-16 04:19:57 -07:00
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{
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2017-05-03 15:56:19 -06:00
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if (PageHuge(p))
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return;
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2009-12-16 04:19:57 -07:00
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if (!PageSlab(p)) {
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lru_add_drain_all();
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if (PageLRU(p))
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return;
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2014-12-10 16:43:10 -07:00
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drain_all_pages(page_zone(p));
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2009-12-16 04:19:57 -07:00
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if (PageLRU(p) || is_free_buddy_page(p))
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return;
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}
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2009-12-16 04:20:00 -07:00
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2009-12-16 04:19:57 -07:00
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/*
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mm: vmscan: invoke slab shrinkers from shrink_zone()
The slab shrinkers are currently invoked from the zonelist walkers in
kswapd, direct reclaim, and zone reclaim, all of which roughly gauge the
eligible LRU pages and assemble a nodemask to pass to NUMA-aware
shrinkers, which then again have to walk over the nodemask. This is
redundant code, extra runtime work, and fairly inaccurate when it comes to
the estimation of actually scannable LRU pages. The code duplication will
only get worse when making the shrinkers cgroup-aware and requiring them
to have out-of-band cgroup hierarchy walks as well.
Instead, invoke the shrinkers from shrink_zone(), which is where all
reclaimers end up, to avoid this duplication.
Take the count for eligible LRU pages out of get_scan_count(), which
considers many more factors than just the availability of swap space, like
zone_reclaimable_pages() currently does. Accumulate the number over all
visited lruvecs to get the per-zone value.
Some nodes have multiple zones due to memory addressing restrictions. To
avoid putting too much pressure on the shrinkers, only invoke them once
for each such node, using the class zone of the allocation as the pivot
zone.
For now, this integrates the slab shrinking better into the reclaim logic
and gets rid of duplicative invocations from kswapd, direct reclaim, and
zone reclaim. It also prepares for cgroup-awareness, allowing
memcg-capable shrinkers to be added at the lruvec level without much
duplication of both code and runtime work.
This changes kswapd behavior, which used to invoke the shrinkers for each
zone, but with scan ratios gathered from the entire node, resulting in
meaningless pressure quantities on multi-zone nodes.
Zone reclaim behavior also changes. It used to shrink slabs until the
same amount of pages were shrunk as were reclaimed from the LRUs. Now it
merely invokes the shrinkers once with the zone's scan ratio, which makes
the shrinkers go easier on caches that implement aging and would prefer
feeding back pressure from recently used slab objects to unused LRU pages.
[vdavydov@parallels.com: assure class zone is populated]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-12 17:56:13 -07:00
|
|
|
* Only call shrink_node_slabs here (which would also shrink
|
|
|
|
* other caches) if access is not potentially fatal.
|
2009-12-16 04:19:57 -07:00
|
|
|
*/
|
2015-02-12 15:58:54 -07:00
|
|
|
if (access)
|
|
|
|
drop_slab_node(page_to_nid(p));
|
2009-12-16 04:19:57 -07:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(shake_page);
|
|
|
|
|
2009-09-16 03:50:15 -06:00
|
|
|
/*
|
|
|
|
* Kill all processes that have a poisoned page mapped and then isolate
|
|
|
|
* the page.
|
|
|
|
*
|
|
|
|
* General strategy:
|
|
|
|
* Find all processes having the page mapped and kill them.
|
|
|
|
* But we keep a page reference around so that the page is not
|
|
|
|
* actually freed yet.
|
|
|
|
* Then stash the page away
|
|
|
|
*
|
|
|
|
* There's no convenient way to get back to mapped processes
|
|
|
|
* from the VMAs. So do a brute-force search over all
|
|
|
|
* running processes.
|
|
|
|
*
|
|
|
|
* Remember that machine checks are not common (or rather
|
|
|
|
* if they are common you have other problems), so this shouldn't
|
|
|
|
* be a performance issue.
|
|
|
|
*
|
|
|
|
* Also there are some races possible while we get from the
|
|
|
|
* error detection to actually handle it.
|
|
|
|
*/
|
|
|
|
|
|
|
|
struct to_kill {
|
|
|
|
struct list_head nd;
|
|
|
|
struct task_struct *tsk;
|
|
|
|
unsigned long addr;
|
2010-09-27 15:36:05 -06:00
|
|
|
char addr_valid;
|
2009-09-16 03:50:15 -06:00
|
|
|
};
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Failure handling: if we can't find or can't kill a process there's
|
|
|
|
* not much we can do. We just print a message and ignore otherwise.
|
|
|
|
*/
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Schedule a process for later kill.
|
|
|
|
* Uses GFP_ATOMIC allocations to avoid potential recursions in the VM.
|
|
|
|
* TBD would GFP_NOIO be enough?
|
|
|
|
*/
|
|
|
|
static void add_to_kill(struct task_struct *tsk, struct page *p,
|
|
|
|
struct vm_area_struct *vma,
|
|
|
|
struct list_head *to_kill,
|
|
|
|
struct to_kill **tkc)
|
|
|
|
{
|
|
|
|
struct to_kill *tk;
|
|
|
|
|
|
|
|
if (*tkc) {
|
|
|
|
tk = *tkc;
|
|
|
|
*tkc = NULL;
|
|
|
|
} else {
|
|
|
|
tk = kmalloc(sizeof(struct to_kill), GFP_ATOMIC);
|
|
|
|
if (!tk) {
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_err("Memory failure: Out of memory while machine check handling\n");
|
2009-09-16 03:50:15 -06:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
tk->addr = page_address_in_vma(p, vma);
|
|
|
|
tk->addr_valid = 1;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* In theory we don't have to kill when the page was
|
|
|
|
* munmaped. But it could be also a mremap. Since that's
|
|
|
|
* likely very rare kill anyways just out of paranoia, but use
|
|
|
|
* a SIGKILL because the error is not contained anymore.
|
|
|
|
*/
|
|
|
|
if (tk->addr == -EFAULT) {
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_info("Memory failure: Unable to find user space address %lx in %s\n",
|
2009-09-16 03:50:15 -06:00
|
|
|
page_to_pfn(p), tsk->comm);
|
|
|
|
tk->addr_valid = 0;
|
|
|
|
}
|
|
|
|
get_task_struct(tsk);
|
|
|
|
tk->tsk = tsk;
|
|
|
|
list_add_tail(&tk->nd, to_kill);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Kill the processes that have been collected earlier.
|
|
|
|
*
|
|
|
|
* Only do anything when DOIT is set, otherwise just free the list
|
|
|
|
* (this is used for clean pages which do not need killing)
|
|
|
|
* Also when FAIL is set do a force kill because something went
|
|
|
|
* wrong earlier.
|
|
|
|
*/
|
2012-07-11 11:20:47 -06:00
|
|
|
static void kill_procs(struct list_head *to_kill, int forcekill, int trapno,
|
2017-05-03 15:54:20 -06:00
|
|
|
bool fail, struct page *page, unsigned long pfn,
|
2011-12-13 10:27:58 -07:00
|
|
|
int flags)
|
2009-09-16 03:50:15 -06:00
|
|
|
{
|
|
|
|
struct to_kill *tk, *next;
|
|
|
|
|
|
|
|
list_for_each_entry_safe (tk, next, to_kill, nd) {
|
2012-07-11 11:20:47 -06:00
|
|
|
if (forcekill) {
|
2009-09-16 03:50:15 -06:00
|
|
|
/*
|
tree-wide: fix assorted typos all over the place
That is "success", "unknown", "through", "performance", "[re|un]mapping"
, "access", "default", "reasonable", "[con]currently", "temperature"
, "channel", "[un]used", "application", "example","hierarchy", "therefore"
, "[over|under]flow", "contiguous", "threshold", "enough" and others.
Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-11-14 08:09:05 -07:00
|
|
|
* In case something went wrong with munmapping
|
2009-09-16 03:50:15 -06:00
|
|
|
* make sure the process doesn't catch the
|
|
|
|
* signal and then access the memory. Just kill it.
|
|
|
|
*/
|
|
|
|
if (fail || tk->addr_valid == 0) {
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_err("Memory failure: %#lx: forcibly killing %s:%d because of failure to unmap corrupted page\n",
|
2016-03-17 15:19:50 -06:00
|
|
|
pfn, tk->tsk->comm, tk->tsk->pid);
|
2009-09-16 03:50:15 -06:00
|
|
|
force_sig(SIGKILL, tk->tsk);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* In theory the process could have mapped
|
|
|
|
* something else on the address in-between. We could
|
|
|
|
* check for that, but we need to tell the
|
|
|
|
* process anyways.
|
|
|
|
*/
|
2011-12-13 10:27:58 -07:00
|
|
|
else if (kill_proc(tk->tsk, tk->addr, trapno,
|
|
|
|
pfn, page, flags) < 0)
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_err("Memory failure: %#lx: Cannot send advisory machine check signal to %s:%d\n",
|
2016-03-17 15:19:50 -06:00
|
|
|
pfn, tk->tsk->comm, tk->tsk->pid);
|
2009-09-16 03:50:15 -06:00
|
|
|
}
|
|
|
|
put_task_struct(tk->tsk);
|
|
|
|
kfree(tk);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2014-06-04 17:11:02 -06:00
|
|
|
/*
|
|
|
|
* Find a dedicated thread which is supposed to handle SIGBUS(BUS_MCEERR_AO)
|
|
|
|
* on behalf of the thread group. Return task_struct of the (first found)
|
|
|
|
* dedicated thread if found, and return NULL otherwise.
|
|
|
|
*
|
|
|
|
* We already hold read_lock(&tasklist_lock) in the caller, so we don't
|
|
|
|
* have to call rcu_read_lock/unlock() in this function.
|
|
|
|
*/
|
|
|
|
static struct task_struct *find_early_kill_thread(struct task_struct *tsk)
|
2009-09-16 03:50:15 -06:00
|
|
|
{
|
2014-06-04 17:11:02 -06:00
|
|
|
struct task_struct *t;
|
|
|
|
|
|
|
|
for_each_thread(tsk, t)
|
|
|
|
if ((t->flags & PF_MCE_PROCESS) && (t->flags & PF_MCE_EARLY))
|
|
|
|
return t;
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Determine whether a given process is "early kill" process which expects
|
|
|
|
* to be signaled when some page under the process is hwpoisoned.
|
|
|
|
* Return task_struct of the dedicated thread (main thread unless explicitly
|
|
|
|
* specified) if the process is "early kill," and otherwise returns NULL.
|
|
|
|
*/
|
|
|
|
static struct task_struct *task_early_kill(struct task_struct *tsk,
|
|
|
|
int force_early)
|
|
|
|
{
|
|
|
|
struct task_struct *t;
|
2009-09-16 03:50:15 -06:00
|
|
|
if (!tsk->mm)
|
2014-06-04 17:11:02 -06:00
|
|
|
return NULL;
|
2014-06-04 17:11:01 -06:00
|
|
|
if (force_early)
|
2014-06-04 17:11:02 -06:00
|
|
|
return tsk;
|
|
|
|
t = find_early_kill_thread(tsk);
|
|
|
|
if (t)
|
|
|
|
return t;
|
|
|
|
if (sysctl_memory_failure_early_kill)
|
|
|
|
return tsk;
|
|
|
|
return NULL;
|
2009-09-16 03:50:15 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Collect processes when the error hit an anonymous page.
|
|
|
|
*/
|
|
|
|
static void collect_procs_anon(struct page *page, struct list_head *to_kill,
|
2014-06-04 17:11:01 -06:00
|
|
|
struct to_kill **tkc, int force_early)
|
2009-09-16 03:50:15 -06:00
|
|
|
{
|
|
|
|
struct vm_area_struct *vma;
|
|
|
|
struct task_struct *tsk;
|
|
|
|
struct anon_vma *av;
|
mm anon rmap: replace same_anon_vma linked list with an interval tree.
When a large VMA (anon or private file mapping) is first touched, which
will populate its anon_vma field, and then split into many regions through
the use of mprotect(), the original anon_vma ends up linking all of the
vmas on a linked list. This can cause rmap to become inefficient, as we
have to walk potentially thousands of irrelevent vmas before finding the
one a given anon page might fall into.
By replacing the same_anon_vma linked list with an interval tree (where
each avc's interval is determined by its vma's start and last pgoffs), we
can make rmap efficient for this use case again.
While the change is large, all of its pieces are fairly simple.
Most places that were walking the same_anon_vma list were looking for a
known pgoff, so they can just use the anon_vma_interval_tree_foreach()
interval tree iterator instead. The exception here is ksm, where the
page's index is not known. It would probably be possible to rework ksm so
that the index would be known, but for now I have decided to keep things
simple and just walk the entirety of the interval tree there.
When updating vma's that already have an anon_vma assigned, we must take
care to re-index the corresponding avc's on their interval tree. This is
done through the use of anon_vma_interval_tree_pre_update_vma() and
anon_vma_interval_tree_post_update_vma(), which remove the avc's from
their interval tree before the update and re-insert them after the update.
The anon_vma stays locked during the update, so there is no chance that
rmap would miss the vmas that are being updated.
Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Daniel Santos <daniel.santos@pobox.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-08 17:31:39 -06:00
|
|
|
pgoff_t pgoff;
|
2009-09-16 03:50:15 -06:00
|
|
|
|
2012-12-02 12:56:50 -07:00
|
|
|
av = page_lock_anon_vma_read(page);
|
2009-09-16 03:50:15 -06:00
|
|
|
if (av == NULL) /* Not actually mapped anymore */
|
2011-06-27 17:18:09 -06:00
|
|
|
return;
|
|
|
|
|
2014-07-23 15:00:01 -06:00
|
|
|
pgoff = page_to_pgoff(page);
|
2011-06-27 17:18:09 -06:00
|
|
|
read_lock(&tasklist_lock);
|
2009-09-16 03:50:15 -06:00
|
|
|
for_each_process (tsk) {
|
mm: change anon_vma linking to fix multi-process server scalability issue
The old anon_vma code can lead to scalability issues with heavily forking
workloads. Specifically, each anon_vma will be shared between the parent
process and all its child processes.
In a workload with 1000 child processes and a VMA with 1000 anonymous
pages per process that get COWed, this leads to a system with a million
anonymous pages in the same anon_vma, each of which is mapped in just one
of the 1000 processes. However, the current rmap code needs to walk them
all, leading to O(N) scanning complexity for each page.
This can result in systems where one CPU is walking the page tables of
1000 processes in page_referenced_one, while all other CPUs are stuck on
the anon_vma lock. This leads to catastrophic failure for a benchmark
like AIM7, where the total number of processes can reach in the tens of
thousands. Real workloads are still a factor 10 less process intensive
than AIM7, but they are catching up.
This patch changes the way anon_vmas and VMAs are linked, which allows us
to associate multiple anon_vmas with a VMA. At fork time, each child
process gets its own anon_vmas, in which its COWed pages will be
instantiated. The parents' anon_vma is also linked to the VMA, because
non-COWed pages could be present in any of the children.
This reduces rmap scanning complexity to O(1) for the pages of the 1000
child processes, with O(N) complexity for at most 1/N pages in the system.
This reduces the average scanning cost in heavily forking workloads from
O(N) to 2.
The only real complexity in this patch stems from the fact that linking a
VMA to anon_vmas now involves memory allocations. This means vma_adjust
can fail, if it needs to attach a VMA to anon_vma structures. This in
turn means error handling needs to be added to the calling functions.
A second source of complexity is that, because there can be multiple
anon_vmas, the anon_vma linking in vma_adjust can no longer be done under
"the" anon_vma lock. To prevent the rmap code from walking up an
incomplete VMA, this patch introduces the VM_LOCK_RMAP VMA flag. This bit
flag uses the same slot as the NOMMU VM_MAPPED_COPY, with an ifdef in mm.h
to make sure it is impossible to compile a kernel that needs both symbolic
values for the same bitflag.
Some test results:
Without the anon_vma changes, when AIM7 hits around 9.7k users (on a test
box with 16GB RAM and not quite enough IO), the system ends up running
>99% in system time, with every CPU on the same anon_vma lock in the
pageout code.
With these changes, AIM7 hits the cross-over point around 29.7k users.
This happens with ~99% IO wait time, there never seems to be any spike in
system time. The anon_vma lock contention appears to be resolved.
[akpm@linux-foundation.org: cleanups]
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-05 14:42:07 -07:00
|
|
|
struct anon_vma_chain *vmac;
|
2014-06-04 17:11:02 -06:00
|
|
|
struct task_struct *t = task_early_kill(tsk, force_early);
|
mm: change anon_vma linking to fix multi-process server scalability issue
The old anon_vma code can lead to scalability issues with heavily forking
workloads. Specifically, each anon_vma will be shared between the parent
process and all its child processes.
In a workload with 1000 child processes and a VMA with 1000 anonymous
pages per process that get COWed, this leads to a system with a million
anonymous pages in the same anon_vma, each of which is mapped in just one
of the 1000 processes. However, the current rmap code needs to walk them
all, leading to O(N) scanning complexity for each page.
This can result in systems where one CPU is walking the page tables of
1000 processes in page_referenced_one, while all other CPUs are stuck on
the anon_vma lock. This leads to catastrophic failure for a benchmark
like AIM7, where the total number of processes can reach in the tens of
thousands. Real workloads are still a factor 10 less process intensive
than AIM7, but they are catching up.
This patch changes the way anon_vmas and VMAs are linked, which allows us
to associate multiple anon_vmas with a VMA. At fork time, each child
process gets its own anon_vmas, in which its COWed pages will be
instantiated. The parents' anon_vma is also linked to the VMA, because
non-COWed pages could be present in any of the children.
This reduces rmap scanning complexity to O(1) for the pages of the 1000
child processes, with O(N) complexity for at most 1/N pages in the system.
This reduces the average scanning cost in heavily forking workloads from
O(N) to 2.
The only real complexity in this patch stems from the fact that linking a
VMA to anon_vmas now involves memory allocations. This means vma_adjust
can fail, if it needs to attach a VMA to anon_vma structures. This in
turn means error handling needs to be added to the calling functions.
A second source of complexity is that, because there can be multiple
anon_vmas, the anon_vma linking in vma_adjust can no longer be done under
"the" anon_vma lock. To prevent the rmap code from walking up an
incomplete VMA, this patch introduces the VM_LOCK_RMAP VMA flag. This bit
flag uses the same slot as the NOMMU VM_MAPPED_COPY, with an ifdef in mm.h
to make sure it is impossible to compile a kernel that needs both symbolic
values for the same bitflag.
Some test results:
Without the anon_vma changes, when AIM7 hits around 9.7k users (on a test
box with 16GB RAM and not quite enough IO), the system ends up running
>99% in system time, with every CPU on the same anon_vma lock in the
pageout code.
With these changes, AIM7 hits the cross-over point around 29.7k users.
This happens with ~99% IO wait time, there never seems to be any spike in
system time. The anon_vma lock contention appears to be resolved.
[akpm@linux-foundation.org: cleanups]
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-05 14:42:07 -07:00
|
|
|
|
2014-06-04 17:11:02 -06:00
|
|
|
if (!t)
|
2009-09-16 03:50:15 -06:00
|
|
|
continue;
|
mm anon rmap: replace same_anon_vma linked list with an interval tree.
When a large VMA (anon or private file mapping) is first touched, which
will populate its anon_vma field, and then split into many regions through
the use of mprotect(), the original anon_vma ends up linking all of the
vmas on a linked list. This can cause rmap to become inefficient, as we
have to walk potentially thousands of irrelevent vmas before finding the
one a given anon page might fall into.
By replacing the same_anon_vma linked list with an interval tree (where
each avc's interval is determined by its vma's start and last pgoffs), we
can make rmap efficient for this use case again.
While the change is large, all of its pieces are fairly simple.
Most places that were walking the same_anon_vma list were looking for a
known pgoff, so they can just use the anon_vma_interval_tree_foreach()
interval tree iterator instead. The exception here is ksm, where the
page's index is not known. It would probably be possible to rework ksm so
that the index would be known, but for now I have decided to keep things
simple and just walk the entirety of the interval tree there.
When updating vma's that already have an anon_vma assigned, we must take
care to re-index the corresponding avc's on their interval tree. This is
done through the use of anon_vma_interval_tree_pre_update_vma() and
anon_vma_interval_tree_post_update_vma(), which remove the avc's from
their interval tree before the update and re-insert them after the update.
The anon_vma stays locked during the update, so there is no chance that
rmap would miss the vmas that are being updated.
Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Daniel Santos <daniel.santos@pobox.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-08 17:31:39 -06:00
|
|
|
anon_vma_interval_tree_foreach(vmac, &av->rb_root,
|
|
|
|
pgoff, pgoff) {
|
mm: change anon_vma linking to fix multi-process server scalability issue
The old anon_vma code can lead to scalability issues with heavily forking
workloads. Specifically, each anon_vma will be shared between the parent
process and all its child processes.
In a workload with 1000 child processes and a VMA with 1000 anonymous
pages per process that get COWed, this leads to a system with a million
anonymous pages in the same anon_vma, each of which is mapped in just one
of the 1000 processes. However, the current rmap code needs to walk them
all, leading to O(N) scanning complexity for each page.
This can result in systems where one CPU is walking the page tables of
1000 processes in page_referenced_one, while all other CPUs are stuck on
the anon_vma lock. This leads to catastrophic failure for a benchmark
like AIM7, where the total number of processes can reach in the tens of
thousands. Real workloads are still a factor 10 less process intensive
than AIM7, but they are catching up.
This patch changes the way anon_vmas and VMAs are linked, which allows us
to associate multiple anon_vmas with a VMA. At fork time, each child
process gets its own anon_vmas, in which its COWed pages will be
instantiated. The parents' anon_vma is also linked to the VMA, because
non-COWed pages could be present in any of the children.
This reduces rmap scanning complexity to O(1) for the pages of the 1000
child processes, with O(N) complexity for at most 1/N pages in the system.
This reduces the average scanning cost in heavily forking workloads from
O(N) to 2.
The only real complexity in this patch stems from the fact that linking a
VMA to anon_vmas now involves memory allocations. This means vma_adjust
can fail, if it needs to attach a VMA to anon_vma structures. This in
turn means error handling needs to be added to the calling functions.
A second source of complexity is that, because there can be multiple
anon_vmas, the anon_vma linking in vma_adjust can no longer be done under
"the" anon_vma lock. To prevent the rmap code from walking up an
incomplete VMA, this patch introduces the VM_LOCK_RMAP VMA flag. This bit
flag uses the same slot as the NOMMU VM_MAPPED_COPY, with an ifdef in mm.h
to make sure it is impossible to compile a kernel that needs both symbolic
values for the same bitflag.
Some test results:
Without the anon_vma changes, when AIM7 hits around 9.7k users (on a test
box with 16GB RAM and not quite enough IO), the system ends up running
>99% in system time, with every CPU on the same anon_vma lock in the
pageout code.
With these changes, AIM7 hits the cross-over point around 29.7k users.
This happens with ~99% IO wait time, there never seems to be any spike in
system time. The anon_vma lock contention appears to be resolved.
[akpm@linux-foundation.org: cleanups]
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-05 14:42:07 -07:00
|
|
|
vma = vmac->vma;
|
2009-09-16 03:50:15 -06:00
|
|
|
if (!page_mapped_in_vma(page, vma))
|
|
|
|
continue;
|
2014-06-04 17:11:02 -06:00
|
|
|
if (vma->vm_mm == t->mm)
|
|
|
|
add_to_kill(t, page, vma, to_kill, tkc);
|
2009-09-16 03:50:15 -06:00
|
|
|
}
|
|
|
|
}
|
|
|
|
read_unlock(&tasklist_lock);
|
2012-12-02 12:56:50 -07:00
|
|
|
page_unlock_anon_vma_read(av);
|
2009-09-16 03:50:15 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Collect processes when the error hit a file mapped page.
|
|
|
|
*/
|
|
|
|
static void collect_procs_file(struct page *page, struct list_head *to_kill,
|
2014-06-04 17:11:01 -06:00
|
|
|
struct to_kill **tkc, int force_early)
|
2009-09-16 03:50:15 -06:00
|
|
|
{
|
|
|
|
struct vm_area_struct *vma;
|
|
|
|
struct task_struct *tsk;
|
|
|
|
struct address_space *mapping = page->mapping;
|
|
|
|
|
2014-12-12 17:54:36 -07:00
|
|
|
i_mmap_lock_read(mapping);
|
2011-06-27 17:18:09 -06:00
|
|
|
read_lock(&tasklist_lock);
|
2009-09-16 03:50:15 -06:00
|
|
|
for_each_process(tsk) {
|
2014-07-23 15:00:01 -06:00
|
|
|
pgoff_t pgoff = page_to_pgoff(page);
|
2014-06-04 17:11:02 -06:00
|
|
|
struct task_struct *t = task_early_kill(tsk, force_early);
|
2009-09-16 03:50:15 -06:00
|
|
|
|
2014-06-04 17:11:02 -06:00
|
|
|
if (!t)
|
2009-09-16 03:50:15 -06:00
|
|
|
continue;
|
2012-10-08 17:31:25 -06:00
|
|
|
vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff,
|
2009-09-16 03:50:15 -06:00
|
|
|
pgoff) {
|
|
|
|
/*
|
|
|
|
* Send early kill signal to tasks where a vma covers
|
|
|
|
* the page but the corrupted page is not necessarily
|
|
|
|
* mapped it in its pte.
|
|
|
|
* Assume applications who requested early kill want
|
|
|
|
* to be informed of all such data corruptions.
|
|
|
|
*/
|
2014-06-04 17:11:02 -06:00
|
|
|
if (vma->vm_mm == t->mm)
|
|
|
|
add_to_kill(t, page, vma, to_kill, tkc);
|
2009-09-16 03:50:15 -06:00
|
|
|
}
|
|
|
|
}
|
|
|
|
read_unlock(&tasklist_lock);
|
2014-12-12 17:54:36 -07:00
|
|
|
i_mmap_unlock_read(mapping);
|
2009-09-16 03:50:15 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Collect the processes who have the corrupted page mapped to kill.
|
|
|
|
* This is done in two steps for locking reasons.
|
|
|
|
* First preallocate one tokill structure outside the spin locks,
|
|
|
|
* so that we can kill at least one process reasonably reliable.
|
|
|
|
*/
|
2014-06-04 17:11:01 -06:00
|
|
|
static void collect_procs(struct page *page, struct list_head *tokill,
|
|
|
|
int force_early)
|
2009-09-16 03:50:15 -06:00
|
|
|
{
|
|
|
|
struct to_kill *tk;
|
|
|
|
|
|
|
|
if (!page->mapping)
|
|
|
|
return;
|
|
|
|
|
|
|
|
tk = kmalloc(sizeof(struct to_kill), GFP_NOIO);
|
|
|
|
if (!tk)
|
|
|
|
return;
|
|
|
|
if (PageAnon(page))
|
2014-06-04 17:11:01 -06:00
|
|
|
collect_procs_anon(page, tokill, &tk, force_early);
|
2009-09-16 03:50:15 -06:00
|
|
|
else
|
2014-06-04 17:11:01 -06:00
|
|
|
collect_procs_file(page, tokill, &tk, force_early);
|
2009-09-16 03:50:15 -06:00
|
|
|
kfree(tk);
|
|
|
|
}
|
|
|
|
|
|
|
|
static const char *action_name[] = {
|
2015-06-24 17:57:30 -06:00
|
|
|
[MF_IGNORED] = "Ignored",
|
|
|
|
[MF_FAILED] = "Failed",
|
|
|
|
[MF_DELAYED] = "Delayed",
|
|
|
|
[MF_RECOVERED] = "Recovered",
|
2015-04-15 17:13:05 -06:00
|
|
|
};
|
|
|
|
|
|
|
|
static const char * const action_page_types[] = {
|
2015-06-24 17:57:30 -06:00
|
|
|
[MF_MSG_KERNEL] = "reserved kernel page",
|
|
|
|
[MF_MSG_KERNEL_HIGH_ORDER] = "high-order kernel page",
|
|
|
|
[MF_MSG_SLAB] = "kernel slab page",
|
|
|
|
[MF_MSG_DIFFERENT_COMPOUND] = "different compound page after locking",
|
|
|
|
[MF_MSG_POISONED_HUGE] = "huge page already hardware poisoned",
|
|
|
|
[MF_MSG_HUGE] = "huge page",
|
|
|
|
[MF_MSG_FREE_HUGE] = "free huge page",
|
|
|
|
[MF_MSG_UNMAP_FAILED] = "unmapping failed page",
|
|
|
|
[MF_MSG_DIRTY_SWAPCACHE] = "dirty swapcache page",
|
|
|
|
[MF_MSG_CLEAN_SWAPCACHE] = "clean swapcache page",
|
|
|
|
[MF_MSG_DIRTY_MLOCKED_LRU] = "dirty mlocked LRU page",
|
|
|
|
[MF_MSG_CLEAN_MLOCKED_LRU] = "clean mlocked LRU page",
|
|
|
|
[MF_MSG_DIRTY_UNEVICTABLE_LRU] = "dirty unevictable LRU page",
|
|
|
|
[MF_MSG_CLEAN_UNEVICTABLE_LRU] = "clean unevictable LRU page",
|
|
|
|
[MF_MSG_DIRTY_LRU] = "dirty LRU page",
|
|
|
|
[MF_MSG_CLEAN_LRU] = "clean LRU page",
|
|
|
|
[MF_MSG_TRUNCATED_LRU] = "already truncated LRU page",
|
|
|
|
[MF_MSG_BUDDY] = "free buddy page",
|
|
|
|
[MF_MSG_BUDDY_2ND] = "free buddy page (2nd try)",
|
|
|
|
[MF_MSG_UNKNOWN] = "unknown page",
|
2015-04-15 17:13:05 -06:00
|
|
|
};
|
|
|
|
|
2009-12-16 04:19:58 -07:00
|
|
|
/*
|
|
|
|
* XXX: It is possible that a page is isolated from LRU cache,
|
|
|
|
* and then kept in swap cache or failed to remove from page cache.
|
|
|
|
* The page count will stop it from being freed by unpoison.
|
|
|
|
* Stress tests should be aware of this memory leak problem.
|
|
|
|
*/
|
|
|
|
static int delete_from_lru_cache(struct page *p)
|
|
|
|
{
|
|
|
|
if (!isolate_lru_page(p)) {
|
|
|
|
/*
|
|
|
|
* Clear sensible page flags, so that the buddy system won't
|
|
|
|
* complain when the page is unpoison-and-freed.
|
|
|
|
*/
|
|
|
|
ClearPageActive(p);
|
|
|
|
ClearPageUnevictable(p);
|
|
|
|
/*
|
|
|
|
* drop the page count elevated by isolate_lru_page()
|
|
|
|
*/
|
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 06:29:47 -06:00
|
|
|
put_page(p);
|
2009-12-16 04:19:58 -07:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
return -EIO;
|
|
|
|
}
|
|
|
|
|
2009-09-16 03:50:15 -06:00
|
|
|
/*
|
|
|
|
* Error hit kernel page.
|
|
|
|
* Do nothing, try to be lucky and not touch this instead. For a few cases we
|
|
|
|
* could be more sophisticated.
|
|
|
|
*/
|
|
|
|
static int me_kernel(struct page *p, unsigned long pfn)
|
|
|
|
{
|
2015-06-24 17:57:30 -06:00
|
|
|
return MF_IGNORED;
|
2009-09-16 03:50:15 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Page in unknown state. Do nothing.
|
|
|
|
*/
|
|
|
|
static int me_unknown(struct page *p, unsigned long pfn)
|
|
|
|
{
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_err("Memory failure: %#lx: Unknown page state\n", pfn);
|
2015-06-24 17:57:30 -06:00
|
|
|
return MF_FAILED;
|
2009-09-16 03:50:15 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Clean (or cleaned) page cache page.
|
|
|
|
*/
|
|
|
|
static int me_pagecache_clean(struct page *p, unsigned long pfn)
|
|
|
|
{
|
|
|
|
int err;
|
2015-06-24 17:57:30 -06:00
|
|
|
int ret = MF_FAILED;
|
2009-09-16 03:50:15 -06:00
|
|
|
struct address_space *mapping;
|
|
|
|
|
2009-12-16 04:19:58 -07:00
|
|
|
delete_from_lru_cache(p);
|
|
|
|
|
2009-09-16 03:50:15 -06:00
|
|
|
/*
|
|
|
|
* For anonymous pages we're done the only reference left
|
|
|
|
* should be the one m_f() holds.
|
|
|
|
*/
|
|
|
|
if (PageAnon(p))
|
2015-06-24 17:57:30 -06:00
|
|
|
return MF_RECOVERED;
|
2009-09-16 03:50:15 -06:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Now truncate the page in the page cache. This is really
|
|
|
|
* more like a "temporary hole punch"
|
|
|
|
* Don't do this for block devices when someone else
|
|
|
|
* has a reference, because it could be file system metadata
|
|
|
|
* and that's not safe to truncate.
|
|
|
|
*/
|
|
|
|
mapping = page_mapping(p);
|
|
|
|
if (!mapping) {
|
|
|
|
/*
|
|
|
|
* Page has been teared down in the meanwhile
|
|
|
|
*/
|
2015-06-24 17:57:30 -06:00
|
|
|
return MF_FAILED;
|
2009-09-16 03:50:15 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Truncation is a bit tricky. Enable it per file system for now.
|
|
|
|
*
|
|
|
|
* Open: to take i_mutex or not for this? Right now we don't.
|
|
|
|
*/
|
|
|
|
if (mapping->a_ops->error_remove_page) {
|
|
|
|
err = mapping->a_ops->error_remove_page(mapping, p);
|
|
|
|
if (err != 0) {
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_info("Memory failure: %#lx: Failed to punch page: %d\n",
|
2016-03-17 15:19:50 -06:00
|
|
|
pfn, err);
|
2009-09-16 03:50:15 -06:00
|
|
|
} else if (page_has_private(p) &&
|
|
|
|
!try_to_release_page(p, GFP_NOIO)) {
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_info("Memory failure: %#lx: failed to release buffers\n",
|
|
|
|
pfn);
|
2009-09-16 03:50:15 -06:00
|
|
|
} else {
|
2015-06-24 17:57:30 -06:00
|
|
|
ret = MF_RECOVERED;
|
2009-09-16 03:50:15 -06:00
|
|
|
}
|
|
|
|
} else {
|
|
|
|
/*
|
|
|
|
* If the file system doesn't support it just invalidate
|
|
|
|
* This fails on dirty or anything with private pages
|
|
|
|
*/
|
|
|
|
if (invalidate_inode_page(p))
|
2015-06-24 17:57:30 -06:00
|
|
|
ret = MF_RECOVERED;
|
2009-09-16 03:50:15 -06:00
|
|
|
else
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_info("Memory failure: %#lx: Failed to invalidate\n",
|
|
|
|
pfn);
|
2009-09-16 03:50:15 -06:00
|
|
|
}
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
2014-01-21 16:49:08 -07:00
|
|
|
* Dirty pagecache page
|
2009-09-16 03:50:15 -06:00
|
|
|
* Issues: when the error hit a hole page the error is not properly
|
|
|
|
* propagated.
|
|
|
|
*/
|
|
|
|
static int me_pagecache_dirty(struct page *p, unsigned long pfn)
|
|
|
|
{
|
|
|
|
struct address_space *mapping = page_mapping(p);
|
|
|
|
|
|
|
|
SetPageError(p);
|
|
|
|
/* TBD: print more information about the file. */
|
|
|
|
if (mapping) {
|
|
|
|
/*
|
|
|
|
* IO error will be reported by write(), fsync(), etc.
|
|
|
|
* who check the mapping.
|
|
|
|
* This way the application knows that something went
|
|
|
|
* wrong with its dirty file data.
|
|
|
|
*
|
|
|
|
* There's one open issue:
|
|
|
|
*
|
|
|
|
* The EIO will be only reported on the next IO
|
|
|
|
* operation and then cleared through the IO map.
|
|
|
|
* Normally Linux has two mechanisms to pass IO error
|
|
|
|
* first through the AS_EIO flag in the address space
|
|
|
|
* and then through the PageError flag in the page.
|
|
|
|
* Since we drop pages on memory failure handling the
|
|
|
|
* only mechanism open to use is through AS_AIO.
|
|
|
|
*
|
|
|
|
* This has the disadvantage that it gets cleared on
|
|
|
|
* the first operation that returns an error, while
|
|
|
|
* the PageError bit is more sticky and only cleared
|
|
|
|
* when the page is reread or dropped. If an
|
|
|
|
* application assumes it will always get error on
|
|
|
|
* fsync, but does other operations on the fd before
|
2011-03-30 19:57:33 -06:00
|
|
|
* and the page is dropped between then the error
|
2009-09-16 03:50:15 -06:00
|
|
|
* will not be properly reported.
|
|
|
|
*
|
|
|
|
* This can already happen even without hwpoisoned
|
|
|
|
* pages: first on metadata IO errors (which only
|
|
|
|
* report through AS_EIO) or when the page is dropped
|
|
|
|
* at the wrong time.
|
|
|
|
*
|
|
|
|
* So right now we assume that the application DTRT on
|
|
|
|
* the first EIO, but we're not worse than other parts
|
|
|
|
* of the kernel.
|
|
|
|
*/
|
|
|
|
mapping_set_error(mapping, EIO);
|
|
|
|
}
|
|
|
|
|
|
|
|
return me_pagecache_clean(p, pfn);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Clean and dirty swap cache.
|
|
|
|
*
|
|
|
|
* Dirty swap cache page is tricky to handle. The page could live both in page
|
|
|
|
* cache and swap cache(ie. page is freshly swapped in). So it could be
|
|
|
|
* referenced concurrently by 2 types of PTEs:
|
|
|
|
* normal PTEs and swap PTEs. We try to handle them consistently by calling
|
|
|
|
* try_to_unmap(TTU_IGNORE_HWPOISON) to convert the normal PTEs to swap PTEs,
|
|
|
|
* and then
|
|
|
|
* - clear dirty bit to prevent IO
|
|
|
|
* - remove from LRU
|
|
|
|
* - but keep in the swap cache, so that when we return to it on
|
|
|
|
* a later page fault, we know the application is accessing
|
|
|
|
* corrupted data and shall be killed (we installed simple
|
|
|
|
* interception code in do_swap_page to catch it).
|
|
|
|
*
|
|
|
|
* Clean swap cache pages can be directly isolated. A later page fault will
|
|
|
|
* bring in the known good data from disk.
|
|
|
|
*/
|
|
|
|
static int me_swapcache_dirty(struct page *p, unsigned long pfn)
|
|
|
|
{
|
|
|
|
ClearPageDirty(p);
|
|
|
|
/* Trigger EIO in shmem: */
|
|
|
|
ClearPageUptodate(p);
|
|
|
|
|
2009-12-16 04:19:58 -07:00
|
|
|
if (!delete_from_lru_cache(p))
|
2015-06-24 17:57:30 -06:00
|
|
|
return MF_DELAYED;
|
2009-12-16 04:19:58 -07:00
|
|
|
else
|
2015-06-24 17:57:30 -06:00
|
|
|
return MF_FAILED;
|
2009-09-16 03:50:15 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
static int me_swapcache_clean(struct page *p, unsigned long pfn)
|
|
|
|
{
|
|
|
|
delete_from_swap_cache(p);
|
2009-09-28 23:16:20 -06:00
|
|
|
|
2009-12-16 04:19:58 -07:00
|
|
|
if (!delete_from_lru_cache(p))
|
2015-06-24 17:57:30 -06:00
|
|
|
return MF_RECOVERED;
|
2009-12-16 04:19:58 -07:00
|
|
|
else
|
2015-06-24 17:57:30 -06:00
|
|
|
return MF_FAILED;
|
2009-09-16 03:50:15 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Huge pages. Needs work.
|
|
|
|
* Issues:
|
2010-05-27 18:29:20 -06:00
|
|
|
* - Error on hugepage is contained in hugepage unit (not in raw page unit.)
|
|
|
|
* To narrow down kill region to one page, we need to break up pmd.
|
2009-09-16 03:50:15 -06:00
|
|
|
*/
|
|
|
|
static int me_huge_page(struct page *p, unsigned long pfn)
|
|
|
|
{
|
2010-09-07 19:19:36 -06:00
|
|
|
int res = 0;
|
2010-05-27 18:29:20 -06:00
|
|
|
struct page *hpage = compound_head(p);
|
2015-06-24 17:56:53 -06:00
|
|
|
|
|
|
|
if (!PageHuge(hpage))
|
|
|
|
return MF_DELAYED;
|
|
|
|
|
2010-05-27 18:29:20 -06:00
|
|
|
/*
|
|
|
|
* We can safely recover from error on free or reserved (i.e.
|
|
|
|
* not in-use) hugepage by dequeuing it from freelist.
|
|
|
|
* To check whether a hugepage is in-use or not, we can't use
|
|
|
|
* page->lru because it can be used in other hugepage operations,
|
|
|
|
* such as __unmap_hugepage_range() and gather_surplus_pages().
|
|
|
|
* So instead we use page_mapping() and PageAnon().
|
|
|
|
*/
|
|
|
|
if (!(page_mapping(hpage) || PageAnon(hpage))) {
|
2010-09-07 19:19:36 -06:00
|
|
|
res = dequeue_hwpoisoned_huge_page(hpage);
|
|
|
|
if (!res)
|
2015-06-24 17:57:30 -06:00
|
|
|
return MF_RECOVERED;
|
2010-05-27 18:29:20 -06:00
|
|
|
}
|
2015-06-24 17:57:30 -06:00
|
|
|
return MF_DELAYED;
|
2009-09-16 03:50:15 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Various page states we can handle.
|
|
|
|
*
|
|
|
|
* A page state is defined by its current page->flags bits.
|
|
|
|
* The table matches them in order and calls the right handler.
|
|
|
|
*
|
|
|
|
* This is quite tricky because we can access page at any time
|
2011-03-30 19:57:33 -06:00
|
|
|
* in its live cycle, so all accesses have to be extremely careful.
|
2009-09-16 03:50:15 -06:00
|
|
|
*
|
|
|
|
* This is not complete. More states could be added.
|
|
|
|
* For any missing state don't attempt recovery.
|
|
|
|
*/
|
|
|
|
|
|
|
|
#define dirty (1UL << PG_dirty)
|
2016-12-24 20:00:29 -07:00
|
|
|
#define sc ((1UL << PG_swapcache) | (1UL << PG_swapbacked))
|
2009-09-16 03:50:15 -06:00
|
|
|
#define unevict (1UL << PG_unevictable)
|
|
|
|
#define mlock (1UL << PG_mlocked)
|
|
|
|
#define writeback (1UL << PG_writeback)
|
|
|
|
#define lru (1UL << PG_lru)
|
|
|
|
#define head (1UL << PG_head)
|
|
|
|
#define slab (1UL << PG_slab)
|
|
|
|
#define reserved (1UL << PG_reserved)
|
|
|
|
|
|
|
|
static struct page_state {
|
|
|
|
unsigned long mask;
|
|
|
|
unsigned long res;
|
2015-06-24 17:57:30 -06:00
|
|
|
enum mf_action_page_type type;
|
2009-09-16 03:50:15 -06:00
|
|
|
int (*action)(struct page *p, unsigned long pfn);
|
|
|
|
} error_states[] = {
|
2015-06-24 17:57:30 -06:00
|
|
|
{ reserved, reserved, MF_MSG_KERNEL, me_kernel },
|
2009-12-16 04:19:58 -07:00
|
|
|
/*
|
|
|
|
* free pages are specially detected outside this table:
|
|
|
|
* PG_buddy pages only make a small fraction of all free pages.
|
|
|
|
*/
|
2009-09-16 03:50:15 -06:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Could in theory check if slab page is free or if we can drop
|
|
|
|
* currently unused objects without touching them. But just
|
|
|
|
* treat it as standard kernel for now.
|
|
|
|
*/
|
2015-06-24 17:57:30 -06:00
|
|
|
{ slab, slab, MF_MSG_SLAB, me_kernel },
|
2009-09-16 03:50:15 -06:00
|
|
|
|
2015-06-24 17:57:30 -06:00
|
|
|
{ head, head, MF_MSG_HUGE, me_huge_page },
|
2009-09-16 03:50:15 -06:00
|
|
|
|
2015-06-24 17:57:30 -06:00
|
|
|
{ sc|dirty, sc|dirty, MF_MSG_DIRTY_SWAPCACHE, me_swapcache_dirty },
|
|
|
|
{ sc|dirty, sc, MF_MSG_CLEAN_SWAPCACHE, me_swapcache_clean },
|
2009-09-16 03:50:15 -06:00
|
|
|
|
2015-06-24 17:57:30 -06:00
|
|
|
{ mlock|dirty, mlock|dirty, MF_MSG_DIRTY_MLOCKED_LRU, me_pagecache_dirty },
|
|
|
|
{ mlock|dirty, mlock, MF_MSG_CLEAN_MLOCKED_LRU, me_pagecache_clean },
|
2009-09-16 03:50:15 -06:00
|
|
|
|
2015-06-24 17:57:30 -06:00
|
|
|
{ unevict|dirty, unevict|dirty, MF_MSG_DIRTY_UNEVICTABLE_LRU, me_pagecache_dirty },
|
|
|
|
{ unevict|dirty, unevict, MF_MSG_CLEAN_UNEVICTABLE_LRU, me_pagecache_clean },
|
2013-02-22 17:35:53 -07:00
|
|
|
|
2015-06-24 17:57:30 -06:00
|
|
|
{ lru|dirty, lru|dirty, MF_MSG_DIRTY_LRU, me_pagecache_dirty },
|
|
|
|
{ lru|dirty, lru, MF_MSG_CLEAN_LRU, me_pagecache_clean },
|
2009-09-16 03:50:15 -06:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Catchall entry: must be at end.
|
|
|
|
*/
|
2015-06-24 17:57:30 -06:00
|
|
|
{ 0, 0, MF_MSG_UNKNOWN, me_unknown },
|
2009-09-16 03:50:15 -06:00
|
|
|
};
|
|
|
|
|
2009-12-16 04:20:00 -07:00
|
|
|
#undef dirty
|
|
|
|
#undef sc
|
|
|
|
#undef unevict
|
|
|
|
#undef mlock
|
|
|
|
#undef writeback
|
|
|
|
#undef lru
|
|
|
|
#undef head
|
|
|
|
#undef slab
|
|
|
|
#undef reserved
|
|
|
|
|
2012-12-11 17:01:32 -07:00
|
|
|
/*
|
|
|
|
* "Dirty/Clean" indication is not 100% accurate due to the possibility of
|
|
|
|
* setting PG_dirty outside page lock. See also comment above set_page_dirty().
|
|
|
|
*/
|
2015-06-24 17:57:33 -06:00
|
|
|
static void action_result(unsigned long pfn, enum mf_action_page_type type,
|
|
|
|
enum mf_result result)
|
2009-09-16 03:50:15 -06:00
|
|
|
{
|
2015-06-24 17:57:36 -06:00
|
|
|
trace_memory_failure_event(pfn, type, result);
|
|
|
|
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_err("Memory failure: %#lx: recovery action for %s: %s\n",
|
2015-04-15 17:13:05 -06:00
|
|
|
pfn, action_page_types[type], action_name[result]);
|
2009-09-16 03:50:15 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
static int page_action(struct page_state *ps, struct page *p,
|
2009-12-16 04:19:57 -07:00
|
|
|
unsigned long pfn)
|
2009-09-16 03:50:15 -06:00
|
|
|
{
|
|
|
|
int result;
|
2009-10-19 00:15:01 -06:00
|
|
|
int count;
|
2009-09-16 03:50:15 -06:00
|
|
|
|
|
|
|
result = ps->action(p, pfn);
|
2009-10-19 00:15:01 -06:00
|
|
|
|
2009-12-16 04:19:57 -07:00
|
|
|
count = page_count(p) - 1;
|
2015-06-24 17:57:30 -06:00
|
|
|
if (ps->action == me_swapcache_dirty && result == MF_DELAYED)
|
2009-12-16 04:19:58 -07:00
|
|
|
count--;
|
|
|
|
if (count != 0) {
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_err("Memory failure: %#lx: %s still referenced by %d users\n",
|
2015-04-15 17:13:05 -06:00
|
|
|
pfn, action_page_types[ps->type], count);
|
2015-06-24 17:57:30 -06:00
|
|
|
result = MF_FAILED;
|
2009-12-16 04:19:58 -07:00
|
|
|
}
|
2015-04-15 17:13:05 -06:00
|
|
|
action_result(pfn, ps->type, result);
|
2009-09-16 03:50:15 -06:00
|
|
|
|
|
|
|
/* Could do more checks here if page looks ok */
|
|
|
|
/*
|
|
|
|
* Could adjust zone counters here to correct for the missing page.
|
|
|
|
*/
|
|
|
|
|
2015-06-24 17:57:30 -06:00
|
|
|
return (result == MF_RECOVERED || result == MF_DELAYED) ? 0 : -EBUSY;
|
2009-09-16 03:50:15 -06:00
|
|
|
}
|
|
|
|
|
2015-06-24 17:56:48 -06:00
|
|
|
/**
|
|
|
|
* get_hwpoison_page() - Get refcount for memory error handling:
|
|
|
|
* @page: raw error page (hit by memory error)
|
|
|
|
*
|
|
|
|
* Return: return 0 if failed to grab the refcount, otherwise true (some
|
|
|
|
* non-zero value.)
|
|
|
|
*/
|
|
|
|
int get_hwpoison_page(struct page *page)
|
|
|
|
{
|
|
|
|
struct page *head = compound_head(page);
|
|
|
|
|
2016-01-15 17:54:07 -07:00
|
|
|
if (!PageHuge(head) && PageTransHuge(head)) {
|
2015-08-06 16:47:04 -06:00
|
|
|
/*
|
|
|
|
* Non anonymous thp exists only in allocation/free time. We
|
|
|
|
* can't handle such a case correctly, so let's give it up.
|
|
|
|
* This should be better than triggering BUG_ON when kernel
|
|
|
|
* tries to touch the "partially handled" page.
|
|
|
|
*/
|
|
|
|
if (!PageAnon(head)) {
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_err("Memory failure: %#lx: non anonymous thp\n",
|
2015-08-06 16:47:04 -06:00
|
|
|
page_to_pfn(page));
|
|
|
|
return 0;
|
|
|
|
}
|
2015-06-24 17:56:48 -06:00
|
|
|
}
|
|
|
|
|
2016-04-28 17:19:03 -06:00
|
|
|
if (get_page_unless_zero(head)) {
|
|
|
|
if (head == compound_head(page))
|
|
|
|
return 1;
|
|
|
|
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_info("Memory failure: %#lx cannot catch tail\n",
|
|
|
|
page_to_pfn(page));
|
2016-04-28 17:19:03 -06:00
|
|
|
put_page(head);
|
|
|
|
}
|
|
|
|
|
|
|
|
return 0;
|
2015-06-24 17:56:48 -06:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(get_hwpoison_page);
|
|
|
|
|
2009-09-16 03:50:15 -06:00
|
|
|
/*
|
|
|
|
* Do all that is necessary to remove user space mappings. Unmap
|
|
|
|
* the pages and send SIGBUS to the processes if the data was dirty.
|
|
|
|
*/
|
2017-05-03 15:54:20 -06:00
|
|
|
static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
|
2014-01-23 16:53:14 -07:00
|
|
|
int trapno, int flags, struct page **hpagep)
|
2009-09-16 03:50:15 -06:00
|
|
|
{
|
mm: delete unnecessary TTU_* flags
Patch series "mm: fix some MADV_FREE issues", v5.
We are trying to use MADV_FREE in jemalloc. Several issues are found.
Without solving the issues, jemalloc can't use the MADV_FREE feature.
- Doesn't support system without swap enabled. Because if swap is off,
we can't or can't efficiently age anonymous pages. And since
MADV_FREE pages are mixed with other anonymous pages, we can't
reclaim MADV_FREE pages. In current implementation, MADV_FREE will
fallback to MADV_DONTNEED without swap enabled. But in our
environment, a lot of machines don't enable swap. This will prevent
our setup using MADV_FREE.
- Increases memory pressure. page reclaim bias file pages reclaim
against anonymous pages. This doesn't make sense for MADV_FREE pages,
because those pages could be freed easily and refilled with very
slight penality. Even page reclaim doesn't bias file pages, there is
still an issue, because MADV_FREE pages and other anonymous pages are
mixed together. To reclaim a MADV_FREE page, we probably must scan a
lot of other anonymous pages, which is inefficient. In our test, we
usually see oom with MADV_FREE enabled and nothing without it.
- Accounting. There are two accounting problems. We don't have a global
accounting. If the system is abnormal, we don't know if it's a
problem from MADV_FREE side. The other problem is RSS accounting.
MADV_FREE pages are accounted as normal anon pages and reclaimed
lazily, so application's RSS becomes bigger. This confuses our
workloads. We have monitoring daemon running and if it finds
applications' RSS becomes abnormal, the daemon will kill the
applications even kernel can reclaim the memory easily.
To address the first the two issues, we can either put MADV_FREE pages
into a separate LRU list (Minchan's previous patches and V1 patches), or
put them into LRU_INACTIVE_FILE list (suggested by Johannes). The
patchset use the second idea. The reason is LRU_INACTIVE_FILE list is
tiny nowadays and should be full of used once file pages. So we can
still efficiently reclaim MADV_FREE pages there without interference
with other anon and active file pages. Putting the pages into inactive
file list also has an advantage which allows page reclaim to prioritize
MADV_FREE pages and used once file pages. MADV_FREE pages are put into
the lru list and clear SwapBacked flag, so PageAnon(page) &&
!PageSwapBacked(page) will indicate a MADV_FREE pages. These pages will
directly freed without pageout if they are clean, otherwise normal swap
will reclaim them.
For the third issue, the previous post adds global accounting and a
separate RSS count for MADV_FREE pages. The problem is we never get
accurate accounting for MADV_FREE pages. The pages are mapped to
userspace, can be dirtied without notice from kernel side. To get
accurate accounting, we could write protect the page, but then there is
extra page fault overhead, which people don't want to pay. Jemalloc
guys have concerns about the inaccurate accounting, so this post drops
the accounting patches temporarily. The info exported to
/proc/pid/smaps for MADV_FREE pages are kept, which is the only place we
can get accurate accounting right now.
This patch (of 6):
Johannes pointed out TTU_LZFREE is unnecessary. It's true because we
always have the flag set if we want to do an unmap. For cases we don't
do an unmap, the TTU_LZFREE part of code should never run.
Also the TTU_UNMAP is unnecessary. If no other flags set (for example,
TTU_MIGRATION), an unmap is implied.
The patch includes Johannes's cleanup and dead TTU_ACTION macro removal
code
Link: http://lkml.kernel.org/r/4be3ea1bc56b26fd98a54d0a6f70bec63f6d8980.1487965799.git.shli@fb.com
Signed-off-by: Shaohua Li <shli@fb.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-03 15:52:22 -06:00
|
|
|
enum ttu_flags ttu = TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS;
|
2009-09-16 03:50:15 -06:00
|
|
|
struct address_space *mapping;
|
|
|
|
LIST_HEAD(tokill);
|
2017-05-03 15:54:20 -06:00
|
|
|
bool unmap_success;
|
2012-07-11 11:20:47 -06:00
|
|
|
int kill = 1, forcekill;
|
2014-01-23 16:53:14 -07:00
|
|
|
struct page *hpage = *hpagep;
|
2017-05-03 15:56:22 -06:00
|
|
|
bool mlocked = PageMlocked(hpage);
|
2009-09-16 03:50:15 -06:00
|
|
|
|
2014-07-30 17:08:28 -06:00
|
|
|
/*
|
|
|
|
* Here we are interested only in user-mapped pages, so skip any
|
|
|
|
* other types of pages.
|
|
|
|
*/
|
|
|
|
if (PageReserved(p) || PageSlab(p))
|
2017-05-03 15:54:20 -06:00
|
|
|
return true;
|
2014-07-30 17:08:28 -06:00
|
|
|
if (!(PageLRU(hpage) || PageHuge(p)))
|
2017-05-03 15:54:20 -06:00
|
|
|
return true;
|
2009-09-16 03:50:15 -06:00
|
|
|
|
|
|
|
/*
|
|
|
|
* This check implies we don't kill processes if their pages
|
|
|
|
* are in the swap cache early. Those are always late kills.
|
|
|
|
*/
|
2010-05-27 18:29:17 -06:00
|
|
|
if (!page_mapped(hpage))
|
2017-05-03 15:54:20 -06:00
|
|
|
return true;
|
2009-12-16 04:19:58 -07:00
|
|
|
|
2014-07-30 17:08:30 -06:00
|
|
|
if (PageKsm(p)) {
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_err("Memory failure: %#lx: can't handle KSM pages.\n", pfn);
|
2017-05-03 15:54:20 -06:00
|
|
|
return false;
|
2014-07-30 17:08:30 -06:00
|
|
|
}
|
2009-09-16 03:50:15 -06:00
|
|
|
|
|
|
|
if (PageSwapCache(p)) {
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_err("Memory failure: %#lx: keeping poisoned page in swap cache\n",
|
|
|
|
pfn);
|
2009-09-16 03:50:15 -06:00
|
|
|
ttu |= TTU_IGNORE_HWPOISON;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Propagate the dirty bit from PTEs to struct page first, because we
|
|
|
|
* need this to decide if we should kill or just drop the page.
|
2009-12-16 04:19:58 -07:00
|
|
|
* XXX: the dirty test could be racy: set_page_dirty() may not always
|
|
|
|
* be called inside page lock (it's recommended but not enforced).
|
2009-09-16 03:50:15 -06:00
|
|
|
*/
|
2010-05-27 18:29:17 -06:00
|
|
|
mapping = page_mapping(hpage);
|
2012-07-11 11:20:47 -06:00
|
|
|
if (!(flags & MF_MUST_KILL) && !PageDirty(hpage) && mapping &&
|
2010-05-27 18:29:17 -06:00
|
|
|
mapping_cap_writeback_dirty(mapping)) {
|
|
|
|
if (page_mkclean(hpage)) {
|
|
|
|
SetPageDirty(hpage);
|
2009-09-16 03:50:15 -06:00
|
|
|
} else {
|
|
|
|
kill = 0;
|
|
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|
ttu |= TTU_IGNORE_HWPOISON;
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_info("Memory failure: %#lx: corrupted page was clean: dropped without side effects\n",
|
2009-09-16 03:50:15 -06:00
|
|
|
pfn);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* First collect all the processes that have the page
|
|
|
|
* mapped in dirty form. This has to be done before try_to_unmap,
|
|
|
|
* because ttu takes the rmap data structures down.
|
|
|
|
*
|
|
|
|
* Error handling: We ignore errors here because
|
|
|
|
* there's nothing that can be done.
|
|
|
|
*/
|
|
|
|
if (kill)
|
2015-06-24 17:56:45 -06:00
|
|
|
collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED);
|
2009-09-16 03:50:15 -06:00
|
|
|
|
2017-05-03 15:54:20 -06:00
|
|
|
unmap_success = try_to_unmap(hpage, ttu);
|
|
|
|
if (!unmap_success)
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_err("Memory failure: %#lx: failed to unmap page (mapcount=%d)\n",
|
2016-03-17 15:19:50 -06:00
|
|
|
pfn, page_mapcount(hpage));
|
2011-02-01 16:52:40 -07:00
|
|
|
|
2017-05-03 15:56:22 -06:00
|
|
|
/*
|
|
|
|
* try_to_unmap() might put mlocked page in lru cache, so call
|
|
|
|
* shake_page() again to ensure that it's flushed.
|
|
|
|
*/
|
|
|
|
if (mlocked)
|
|
|
|
shake_page(hpage, 0);
|
|
|
|
|
2009-09-16 03:50:15 -06:00
|
|
|
/*
|
|
|
|
* Now that the dirty bit has been propagated to the
|
|
|
|
* struct page and all unmaps done we can decide if
|
|
|
|
* killing is needed or not. Only kill when the page
|
2012-07-11 11:20:47 -06:00
|
|
|
* was dirty or the process is not restartable,
|
|
|
|
* otherwise the tokill list is merely
|
2009-09-16 03:50:15 -06:00
|
|
|
* freed. When there was a problem unmapping earlier
|
|
|
|
* use a more force-full uncatchable kill to prevent
|
|
|
|
* any accesses to the poisoned memory.
|
|
|
|
*/
|
2015-06-24 17:56:45 -06:00
|
|
|
forcekill = PageDirty(hpage) || (flags & MF_MUST_KILL);
|
2017-05-03 15:54:20 -06:00
|
|
|
kill_procs(&tokill, forcekill, trapno, !unmap_success, p, pfn, flags);
|
2009-12-16 04:19:58 -07:00
|
|
|
|
2017-05-03 15:54:20 -06:00
|
|
|
return unmap_success;
|
2009-09-16 03:50:15 -06:00
|
|
|
}
|
|
|
|
|
2010-05-27 18:29:18 -06:00
|
|
|
static void set_page_hwpoison_huge_page(struct page *hpage)
|
|
|
|
{
|
|
|
|
int i;
|
2013-09-11 15:22:52 -06:00
|
|
|
int nr_pages = 1 << compound_order(hpage);
|
2010-05-27 18:29:18 -06:00
|
|
|
for (i = 0; i < nr_pages; i++)
|
|
|
|
SetPageHWPoison(hpage + i);
|
|
|
|
}
|
|
|
|
|
|
|
|
static void clear_page_hwpoison_huge_page(struct page *hpage)
|
|
|
|
{
|
|
|
|
int i;
|
2013-09-11 15:22:52 -06:00
|
|
|
int nr_pages = 1 << compound_order(hpage);
|
2010-05-27 18:29:18 -06:00
|
|
|
for (i = 0; i < nr_pages; i++)
|
|
|
|
ClearPageHWPoison(hpage + i);
|
|
|
|
}
|
|
|
|
|
2011-12-15 11:48:12 -07:00
|
|
|
/**
|
|
|
|
* memory_failure - Handle memory failure of a page.
|
|
|
|
* @pfn: Page Number of the corrupted page
|
|
|
|
* @trapno: Trap number reported in the signal to user space.
|
|
|
|
* @flags: fine tune action taken
|
|
|
|
*
|
|
|
|
* This function is called by the low level machine check code
|
|
|
|
* of an architecture when it detects hardware memory corruption
|
|
|
|
* of a page. It tries its best to recover, which includes
|
|
|
|
* dropping pages, killing processes etc.
|
|
|
|
*
|
|
|
|
* The function is primarily of use for corruptions that
|
|
|
|
* happen outside the current execution context (e.g. when
|
|
|
|
* detected by a background scrubber)
|
|
|
|
*
|
|
|
|
* Must run in process context (e.g. a work queue) with interrupts
|
|
|
|
* enabled and no spinlocks hold.
|
|
|
|
*/
|
|
|
|
int memory_failure(unsigned long pfn, int trapno, int flags)
|
2009-09-16 03:50:15 -06:00
|
|
|
{
|
|
|
|
struct page_state *ps;
|
|
|
|
struct page *p;
|
2010-05-27 18:29:17 -06:00
|
|
|
struct page *hpage;
|
2015-06-24 17:56:45 -06:00
|
|
|
struct page *orig_head;
|
2009-09-16 03:50:15 -06:00
|
|
|
int res;
|
2010-05-27 18:29:19 -06:00
|
|
|
unsigned int nr_pages;
|
2013-02-22 17:35:51 -07:00
|
|
|
unsigned long page_flags;
|
2009-09-16 03:50:15 -06:00
|
|
|
|
|
|
|
if (!sysctl_memory_failure_recovery)
|
|
|
|
panic("Memory failure from trap %d on page %lx", trapno, pfn);
|
|
|
|
|
|
|
|
if (!pfn_valid(pfn)) {
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_err("Memory failure: %#lx: memory outside kernel control\n",
|
|
|
|
pfn);
|
2009-12-16 04:19:57 -07:00
|
|
|
return -ENXIO;
|
2009-09-16 03:50:15 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
p = pfn_to_page(pfn);
|
2015-06-24 17:56:45 -06:00
|
|
|
orig_head = hpage = compound_head(p);
|
2009-09-16 03:50:15 -06:00
|
|
|
if (TestSetPageHWPoison(p)) {
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_err("Memory failure: %#lx: already hardware poisoned\n",
|
|
|
|
pfn);
|
2009-09-16 03:50:15 -06:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2013-02-22 17:34:05 -07:00
|
|
|
/*
|
|
|
|
* Currently errors on hugetlbfs pages are measured in hugepage units,
|
|
|
|
* so nr_pages should be 1 << compound_order. OTOH when errors are on
|
|
|
|
* transparent hugepages, they are supposed to be split and error
|
|
|
|
* measurement is done in normal page units. So nr_pages should be one
|
|
|
|
* in this case.
|
|
|
|
*/
|
|
|
|
if (PageHuge(p))
|
|
|
|
nr_pages = 1 << compound_order(hpage);
|
|
|
|
else /* normal page or thp */
|
|
|
|
nr_pages = 1;
|
2015-09-08 16:03:24 -06:00
|
|
|
num_poisoned_pages_add(nr_pages);
|
2009-09-16 03:50:15 -06:00
|
|
|
|
|
|
|
/*
|
|
|
|
* We need/can do nothing about count=0 pages.
|
|
|
|
* 1) it's a free page, and therefore in safe hand:
|
|
|
|
* prep_new_page() will be the gate keeper.
|
2010-09-07 19:19:38 -06:00
|
|
|
* 2) it's a free hugepage, which is also safe:
|
|
|
|
* an affected hugepage will be dequeued from hugepage freelist,
|
|
|
|
* so there's no concern about reusing it ever after.
|
|
|
|
* 3) it's part of a non-compound high order page.
|
2009-09-16 03:50:15 -06:00
|
|
|
* Implies some kernel user: cannot stop them from
|
|
|
|
* R/W the page; let's pray that the page has been
|
|
|
|
* used and will be freed some time later.
|
|
|
|
* In fact it's dangerous to directly bump up page count from 0,
|
|
|
|
* that may make page_freeze_refs()/page_unfreeze_refs() mismatch.
|
|
|
|
*/
|
2015-06-24 17:56:48 -06:00
|
|
|
if (!(flags & MF_COUNT_INCREASED) && !get_hwpoison_page(p)) {
|
2009-12-16 04:19:58 -07:00
|
|
|
if (is_free_buddy_page(p)) {
|
2015-06-24 17:57:30 -06:00
|
|
|
action_result(pfn, MF_MSG_BUDDY, MF_DELAYED);
|
2009-12-16 04:19:58 -07:00
|
|
|
return 0;
|
2010-09-07 19:19:38 -06:00
|
|
|
} else if (PageHuge(hpage)) {
|
|
|
|
/*
|
2014-05-22 12:54:15 -06:00
|
|
|
* Check "filter hit" and "race with other subpage."
|
2010-09-07 19:19:38 -06:00
|
|
|
*/
|
2011-03-10 00:52:07 -07:00
|
|
|
lock_page(hpage);
|
2014-05-22 12:54:15 -06:00
|
|
|
if (PageHWPoison(hpage)) {
|
|
|
|
if ((hwpoison_filter(p) && TestClearPageHWPoison(p))
|
|
|
|
|| (p != hpage && TestSetPageHWPoison(hpage))) {
|
2015-09-08 16:03:24 -06:00
|
|
|
num_poisoned_pages_sub(nr_pages);
|
2014-05-22 12:54:15 -06:00
|
|
|
unlock_page(hpage);
|
|
|
|
return 0;
|
|
|
|
}
|
2010-09-07 19:19:38 -06:00
|
|
|
}
|
|
|
|
set_page_hwpoison_huge_page(hpage);
|
|
|
|
res = dequeue_hwpoisoned_huge_page(hpage);
|
2015-06-24 17:57:30 -06:00
|
|
|
action_result(pfn, MF_MSG_FREE_HUGE,
|
|
|
|
res ? MF_IGNORED : MF_DELAYED);
|
2010-09-07 19:19:38 -06:00
|
|
|
unlock_page(hpage);
|
|
|
|
return res;
|
2009-12-16 04:19:58 -07:00
|
|
|
} else {
|
2015-06-24 17:57:30 -06:00
|
|
|
action_result(pfn, MF_MSG_KERNEL_HIGH_ORDER, MF_IGNORED);
|
2009-12-16 04:19:58 -07:00
|
|
|
return -EBUSY;
|
|
|
|
}
|
2009-09-16 03:50:15 -06:00
|
|
|
}
|
|
|
|
|
2015-06-24 17:56:45 -06:00
|
|
|
if (!PageHuge(p) && PageTransHuge(hpage)) {
|
2016-11-10 11:46:23 -07:00
|
|
|
lock_page(p);
|
|
|
|
if (!PageAnon(p) || unlikely(split_huge_page(p))) {
|
|
|
|
unlock_page(p);
|
|
|
|
if (!PageAnon(p))
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_err("Memory failure: %#lx: non anonymous thp\n",
|
|
|
|
pfn);
|
2015-08-14 16:35:08 -06:00
|
|
|
else
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_err("Memory failure: %#lx: thp split failed\n",
|
|
|
|
pfn);
|
2015-06-24 17:56:48 -06:00
|
|
|
if (TestClearPageHWPoison(p))
|
2015-09-08 16:03:24 -06:00
|
|
|
num_poisoned_pages_sub(nr_pages);
|
2015-09-08 16:03:21 -06:00
|
|
|
put_hwpoison_page(p);
|
2015-06-24 17:56:45 -06:00
|
|
|
return -EBUSY;
|
|
|
|
}
|
2016-11-10 11:46:23 -07:00
|
|
|
unlock_page(p);
|
2015-06-24 17:56:45 -06:00
|
|
|
VM_BUG_ON_PAGE(!page_count(p), p);
|
|
|
|
hpage = compound_head(p);
|
|
|
|
}
|
|
|
|
|
2009-09-28 23:16:20 -06:00
|
|
|
/*
|
|
|
|
* We ignore non-LRU pages for good reasons.
|
|
|
|
* - PG_locked is only well defined for LRU pages and a few others
|
2016-01-15 17:51:24 -07:00
|
|
|
* - to avoid races with __SetPageLocked()
|
2009-09-28 23:16:20 -06:00
|
|
|
* - to avoid races with __SetPageSlab*() (and more non-atomic ops)
|
|
|
|
* The check (unnecessarily) ignores LRU pages being isolated and
|
|
|
|
* walked by the page reclaim code, however that's not a big loss.
|
|
|
|
*/
|
2017-05-03 15:56:19 -06:00
|
|
|
shake_page(p, 0);
|
|
|
|
/* shake_page could have turned it free. */
|
|
|
|
if (!PageLRU(p) && is_free_buddy_page(p)) {
|
|
|
|
if (flags & MF_COUNT_INCREASED)
|
|
|
|
action_result(pfn, MF_MSG_BUDDY, MF_DELAYED);
|
|
|
|
else
|
|
|
|
action_result(pfn, MF_MSG_BUDDY_2ND, MF_DELAYED);
|
|
|
|
return 0;
|
2009-09-28 23:16:20 -06:00
|
|
|
}
|
|
|
|
|
2011-03-10 00:52:07 -07:00
|
|
|
lock_page(hpage);
|
2009-12-16 04:19:58 -07:00
|
|
|
|
2014-08-06 17:06:49 -06:00
|
|
|
/*
|
|
|
|
* The page could have changed compound pages during the locking.
|
|
|
|
* If this happens just bail out.
|
|
|
|
*/
|
2015-06-24 17:56:45 -06:00
|
|
|
if (PageCompound(p) && compound_head(p) != orig_head) {
|
2015-06-24 17:57:30 -06:00
|
|
|
action_result(pfn, MF_MSG_DIFFERENT_COMPOUND, MF_IGNORED);
|
2014-08-06 17:06:49 -06:00
|
|
|
res = -EBUSY;
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
|
2013-02-22 17:35:51 -07:00
|
|
|
/*
|
|
|
|
* We use page flags to determine what action should be taken, but
|
|
|
|
* the flags can be modified by the error containment action. One
|
|
|
|
* example is an mlocked page, where PG_mlocked is cleared by
|
|
|
|
* page_remove_rmap() in try_to_unmap_one(). So to determine page status
|
|
|
|
* correctly, we save a copy of the page flags at this time.
|
|
|
|
*/
|
|
|
|
page_flags = p->flags;
|
|
|
|
|
2009-12-16 04:19:58 -07:00
|
|
|
/*
|
|
|
|
* unpoison always clear PG_hwpoison inside page lock
|
|
|
|
*/
|
|
|
|
if (!PageHWPoison(p)) {
|
2016-05-20 17:57:32 -06:00
|
|
|
pr_err("Memory failure: %#lx: just unpoisoned\n", pfn);
|
2015-09-08 16:03:24 -06:00
|
|
|
num_poisoned_pages_sub(nr_pages);
|
2015-08-06 16:46:58 -06:00
|
|
|
unlock_page(hpage);
|
2015-09-08 16:03:21 -06:00
|
|
|
put_hwpoison_page(hpage);
|
2015-08-06 16:46:58 -06:00
|
|
|
return 0;
|
2009-12-16 04:19:58 -07:00
|
|
|
}
|
2009-12-16 04:19:59 -07:00
|
|
|
if (hwpoison_filter(p)) {
|
|
|
|
if (TestClearPageHWPoison(p))
|
2015-09-08 16:03:24 -06:00
|
|
|
num_poisoned_pages_sub(nr_pages);
|
2010-05-27 18:29:17 -06:00
|
|
|
unlock_page(hpage);
|
2015-09-08 16:03:21 -06:00
|
|
|
put_hwpoison_page(hpage);
|
2009-12-16 04:19:59 -07:00
|
|
|
return 0;
|
|
|
|
}
|
2009-12-16 04:19:58 -07:00
|
|
|
|
hwpoison: fix the handling path of the victimized page frame that belong to non-LRU
Until now, the kernel has the same policy to handle victimized page
frames that belong to kernel-space(reserved/slab-subsystem) or
non-LRU(unknown page state). In other word, the result of handling
either of these victimized page frames is (IGNORED | FAILED), and the
return value of memory_failure() is -EBUSY.
This patch is to avoid that memory_failure() returns very soon due to
the "true" value of (!PageLRU(p)), and it also ensures that
action_result() can report more precise information("reserved kernel",
"kernel slab", and "unknown page state") instead of "non LRU",
especially for memory errors which are detected by memory-scrubbing.
Andi said:
: While running the mcelog test suite on 3.14 I hit the following VM_BUG_ON:
:
: soft_offline: 0x56d4: unknown non LRU page type 3ffff800008000
: page:ffffea000015b400 count:3 mapcount:2097169 mapping: (null) index:0xffff8800056d7000
: page flags: 0x3ffff800004081(locked|slab|head)
: ------------[ cut here ]------------
: kernel BUG at mm/rmap.c:1495!
:
: I think what happened is that a LRU page turned into a slab page in
: parallel with offlining. memory_failure initially tests for this case,
: but doesn't retest later after the page has been locked.
:
: ...
:
: I ran this patch in a loop over night with some stress plus
: the mcelog test suite running in a loop. I cannot guarantee it hit it,
: but it should have given it a good beating.
:
: The kernel survived with no messages, although the mcelog test suite
: got killed at some point because it couldn't fork anymore. Probably
: some unrelated problem.
:
: So the patch is ok for me for .16.
Signed-off-by: Chen Yucong <slaoub@gmail.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-07-02 16:22:37 -06:00
|
|
|
if (!PageHuge(p) && !PageTransTail(p) && !PageLRU(p))
|
|
|
|
goto identify_page_state;
|
|
|
|
|
2010-05-27 18:29:18 -06:00
|
|
|
/*
|
|
|
|
* For error on the tail page, we should set PG_hwpoison
|
|
|
|
* on the head page to show that the hugepage is hwpoisoned
|
|
|
|
*/
|
2011-02-01 16:52:40 -07:00
|
|
|
if (PageHuge(p) && PageTail(p) && TestSetPageHWPoison(hpage)) {
|
2015-06-24 17:57:30 -06:00
|
|
|
action_result(pfn, MF_MSG_POISONED_HUGE, MF_IGNORED);
|
2010-05-27 18:29:18 -06:00
|
|
|
unlock_page(hpage);
|
2015-09-08 16:03:21 -06:00
|
|
|
put_hwpoison_page(hpage);
|
2010-05-27 18:29:18 -06:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
/*
|
|
|
|
* Set PG_hwpoison on all pages in an error hugepage,
|
|
|
|
* because containment is done in hugepage unit for now.
|
|
|
|
* Since we have done TestSetPageHWPoison() for the head page with
|
|
|
|
* page lock held, we can safely set PG_hwpoison bits on tail pages.
|
|
|
|
*/
|
|
|
|
if (PageHuge(p))
|
|
|
|
set_page_hwpoison_huge_page(hpage);
|
|
|
|
|
2014-06-04 17:10:35 -06:00
|
|
|
/*
|
|
|
|
* It's very difficult to mess with pages currently under IO
|
|
|
|
* and in many cases impossible, so we just avoid it here.
|
|
|
|
*/
|
2009-09-16 03:50:15 -06:00
|
|
|
wait_on_page_writeback(p);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Now take care of user space mappings.
|
2011-03-22 17:32:44 -06:00
|
|
|
* Abort on fail: __delete_from_page_cache() assumes unmapped page.
|
2014-01-23 16:53:14 -07:00
|
|
|
*
|
|
|
|
* When the raw error page is thp tail page, hpage points to the raw
|
|
|
|
* page after thp split.
|
2009-09-16 03:50:15 -06:00
|
|
|
*/
|
2017-05-03 15:54:20 -06:00
|
|
|
if (!hwpoison_user_mappings(p, pfn, trapno, flags, &hpage)) {
|
2015-06-24 17:57:30 -06:00
|
|
|
action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED);
|
2009-12-16 04:19:58 -07:00
|
|
|
res = -EBUSY;
|
|
|
|
goto out;
|
|
|
|
}
|
2009-09-16 03:50:15 -06:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Torn down by someone else?
|
|
|
|
*/
|
2009-12-16 04:19:58 -07:00
|
|
|
if (PageLRU(p) && !PageSwapCache(p) && p->mapping == NULL) {
|
2015-06-24 17:57:30 -06:00
|
|
|
action_result(pfn, MF_MSG_TRUNCATED_LRU, MF_IGNORED);
|
2009-12-16 04:19:58 -07:00
|
|
|
res = -EBUSY;
|
2009-09-16 03:50:15 -06:00
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
|
hwpoison: fix the handling path of the victimized page frame that belong to non-LRU
Until now, the kernel has the same policy to handle victimized page
frames that belong to kernel-space(reserved/slab-subsystem) or
non-LRU(unknown page state). In other word, the result of handling
either of these victimized page frames is (IGNORED | FAILED), and the
return value of memory_failure() is -EBUSY.
This patch is to avoid that memory_failure() returns very soon due to
the "true" value of (!PageLRU(p)), and it also ensures that
action_result() can report more precise information("reserved kernel",
"kernel slab", and "unknown page state") instead of "non LRU",
especially for memory errors which are detected by memory-scrubbing.
Andi said:
: While running the mcelog test suite on 3.14 I hit the following VM_BUG_ON:
:
: soft_offline: 0x56d4: unknown non LRU page type 3ffff800008000
: page:ffffea000015b400 count:3 mapcount:2097169 mapping: (null) index:0xffff8800056d7000
: page flags: 0x3ffff800004081(locked|slab|head)
: ------------[ cut here ]------------
: kernel BUG at mm/rmap.c:1495!
:
: I think what happened is that a LRU page turned into a slab page in
: parallel with offlining. memory_failure initially tests for this case,
: but doesn't retest later after the page has been locked.
:
: ...
:
: I ran this patch in a loop over night with some stress plus
: the mcelog test suite running in a loop. I cannot guarantee it hit it,
: but it should have given it a good beating.
:
: The kernel survived with no messages, although the mcelog test suite
: got killed at some point because it couldn't fork anymore. Probably
: some unrelated problem.
:
: So the patch is ok for me for .16.
Signed-off-by: Chen Yucong <slaoub@gmail.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-07-02 16:22:37 -06:00
|
|
|
identify_page_state:
|
2009-09-16 03:50:15 -06:00
|
|
|
res = -EBUSY;
|
2013-02-22 17:35:51 -07:00
|
|
|
/*
|
|
|
|
* The first check uses the current page flags which may not have any
|
|
|
|
* relevant information. The second check with the saved page flagss is
|
|
|
|
* carried out only if the first check can't determine the page status.
|
|
|
|
*/
|
|
|
|
for (ps = error_states;; ps++)
|
|
|
|
if ((p->flags & ps->mask) == ps->res)
|
2009-09-16 03:50:15 -06:00
|
|
|
break;
|
mm/hwpoison: fix loss of PG_dirty for errors on mlocked pages
memory_failure() store the page flag of the error page before doing unmap,
and (only) if the first check with page flags at the time decided the
error page is unknown, it do the second check with the stored page flag
since memory_failure() does unmapping of the error pages before doing
page_action(). This unmapping changes the page state, especially
page_remove_rmap() (called from try_to_unmap_one()) clears PG_mlocked, so
page_action() can't catch mlocked pages after that.
However, memory_failure() can't handle memory errors on dirty mlocked
pages correctly. try_to_unmap_one will move the dirty bit from pte to the
physical page, the second check lose it since it check the stored page
flag. This patch fix it by restore PG_dirty flag to stored page flag if
the page is dirty.
Testcase:
#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <errno.h>
#define PAGES_TO_TEST 2
#define PAGE_SIZE 4096
int main(void)
{
char *mem;
int i;
mem = mmap(NULL, PAGES_TO_TEST * PAGE_SIZE,
PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_LOCKED, 0, 0);
for (i = 0; i < PAGES_TO_TEST; i++)
mem[i * PAGE_SIZE] = 'a';
if (madvise(mem, PAGES_TO_TEST * PAGE_SIZE, MADV_HWPOISON) == -1)
return -1;
return 0;
}
Before patch:
[ 912.839247] Injecting memory failure for page 7dfb8 at 7f6b4e37b000
[ 912.839257] MCE 0x7dfb8: clean mlocked LRU page recovery: Recovered
[ 912.845550] MCE 0x7dfb8: clean mlocked LRU page still referenced by 1 users
[ 912.852586] Injecting memory failure for page 7e6aa at 7f6b4e37c000
[ 912.852594] MCE 0x7e6aa: clean mlocked LRU page recovery: Recovered
[ 912.858936] MCE 0x7e6aa: clean mlocked LRU page still referenced by 1 users
After patch:
[ 163.590225] Injecting memory failure for page 91bc2f at 7f9f5b0e5000
[ 163.590264] MCE 0x91bc2f: dirty mlocked LRU page recovery: Recovered
[ 163.596680] MCE 0x91bc2f: dirty mlocked LRU page still referenced by 1 users
[ 163.603831] Injecting memory failure for page 91cdd3 at 7f9f5b0e6000
[ 163.603852] MCE 0x91cdd3: dirty mlocked LRU page recovery: Recovered
[ 163.610305] MCE 0x91cdd3: dirty mlocked LRU page still referenced by 1 users
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:22:50 -06:00
|
|
|
|
|
|
|
page_flags |= (p->flags & (1UL << PG_dirty));
|
|
|
|
|
2013-02-22 17:35:51 -07:00
|
|
|
if (!ps->mask)
|
|
|
|
for (ps = error_states;; ps++)
|
|
|
|
if ((page_flags & ps->mask) == ps->res)
|
|
|
|
break;
|
|
|
|
res = page_action(ps, p, pfn);
|
2009-09-16 03:50:15 -06:00
|
|
|
out:
|
2010-05-27 18:29:17 -06:00
|
|
|
unlock_page(hpage);
|
2009-09-16 03:50:15 -06:00
|
|
|
return res;
|
|
|
|
}
|
2011-12-15 11:48:12 -07:00
|
|
|
EXPORT_SYMBOL_GPL(memory_failure);
|
2009-12-16 04:19:58 -07:00
|
|
|
|
2011-07-12 23:14:27 -06:00
|
|
|
#define MEMORY_FAILURE_FIFO_ORDER 4
|
|
|
|
#define MEMORY_FAILURE_FIFO_SIZE (1 << MEMORY_FAILURE_FIFO_ORDER)
|
|
|
|
|
|
|
|
struct memory_failure_entry {
|
|
|
|
unsigned long pfn;
|
|
|
|
int trapno;
|
|
|
|
int flags;
|
|
|
|
};
|
|
|
|
|
|
|
|
struct memory_failure_cpu {
|
|
|
|
DECLARE_KFIFO(fifo, struct memory_failure_entry,
|
|
|
|
MEMORY_FAILURE_FIFO_SIZE);
|
|
|
|
spinlock_t lock;
|
|
|
|
struct work_struct work;
|
|
|
|
};
|
|
|
|
|
|
|
|
static DEFINE_PER_CPU(struct memory_failure_cpu, memory_failure_cpu);
|
|
|
|
|
|
|
|
/**
|
|
|
|
* memory_failure_queue - Schedule handling memory failure of a page.
|
|
|
|
* @pfn: Page Number of the corrupted page
|
|
|
|
* @trapno: Trap number reported in the signal to user space.
|
|
|
|
* @flags: Flags for memory failure handling
|
|
|
|
*
|
|
|
|
* This function is called by the low level hardware error handler
|
|
|
|
* when it detects hardware memory corruption of a page. It schedules
|
|
|
|
* the recovering of error page, including dropping pages, killing
|
|
|
|
* processes etc.
|
|
|
|
*
|
|
|
|
* The function is primarily of use for corruptions that
|
|
|
|
* happen outside the current execution context (e.g. when
|
|
|
|
* detected by a background scrubber)
|
|
|
|
*
|
|
|
|
* Can run in IRQ context.
|
|
|
|
*/
|
|
|
|
void memory_failure_queue(unsigned long pfn, int trapno, int flags)
|
|
|
|
{
|
|
|
|
struct memory_failure_cpu *mf_cpu;
|
|
|
|
unsigned long proc_flags;
|
|
|
|
struct memory_failure_entry entry = {
|
|
|
|
.pfn = pfn,
|
|
|
|
.trapno = trapno,
|
|
|
|
.flags = flags,
|
|
|
|
};
|
|
|
|
|
|
|
|
mf_cpu = &get_cpu_var(memory_failure_cpu);
|
|
|
|
spin_lock_irqsave(&mf_cpu->lock, proc_flags);
|
2013-11-14 15:32:17 -07:00
|
|
|
if (kfifo_put(&mf_cpu->fifo, entry))
|
2011-07-12 23:14:27 -06:00
|
|
|
schedule_work_on(smp_processor_id(), &mf_cpu->work);
|
|
|
|
else
|
2013-07-25 12:53:25 -06:00
|
|
|
pr_err("Memory failure: buffer overflow when queuing memory failure at %#lx\n",
|
2011-07-12 23:14:27 -06:00
|
|
|
pfn);
|
|
|
|
spin_unlock_irqrestore(&mf_cpu->lock, proc_flags);
|
|
|
|
put_cpu_var(memory_failure_cpu);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(memory_failure_queue);
|
|
|
|
|
|
|
|
static void memory_failure_work_func(struct work_struct *work)
|
|
|
|
{
|
|
|
|
struct memory_failure_cpu *mf_cpu;
|
|
|
|
struct memory_failure_entry entry = { 0, };
|
|
|
|
unsigned long proc_flags;
|
|
|
|
int gotten;
|
|
|
|
|
2014-06-04 17:07:56 -06:00
|
|
|
mf_cpu = this_cpu_ptr(&memory_failure_cpu);
|
2011-07-12 23:14:27 -06:00
|
|
|
for (;;) {
|
|
|
|
spin_lock_irqsave(&mf_cpu->lock, proc_flags);
|
|
|
|
gotten = kfifo_get(&mf_cpu->fifo, &entry);
|
|
|
|
spin_unlock_irqrestore(&mf_cpu->lock, proc_flags);
|
|
|
|
if (!gotten)
|
|
|
|
break;
|
2013-07-10 03:27:01 -06:00
|
|
|
if (entry.flags & MF_SOFT_OFFLINE)
|
|
|
|
soft_offline_page(pfn_to_page(entry.pfn), entry.flags);
|
|
|
|
else
|
|
|
|
memory_failure(entry.pfn, entry.trapno, entry.flags);
|
2011-07-12 23:14:27 -06:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
static int __init memory_failure_init(void)
|
|
|
|
{
|
|
|
|
struct memory_failure_cpu *mf_cpu;
|
|
|
|
int cpu;
|
|
|
|
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
|
|
mf_cpu = &per_cpu(memory_failure_cpu, cpu);
|
|
|
|
spin_lock_init(&mf_cpu->lock);
|
|
|
|
INIT_KFIFO(mf_cpu->fifo);
|
|
|
|
INIT_WORK(&mf_cpu->work, memory_failure_work_func);
|
|
|
|
}
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
core_initcall(memory_failure_init);
|
|
|
|
|
2015-11-05 19:47:26 -07:00
|
|
|
#define unpoison_pr_info(fmt, pfn, rs) \
|
|
|
|
({ \
|
|
|
|
if (__ratelimit(rs)) \
|
|
|
|
pr_info(fmt, pfn); \
|
|
|
|
})
|
|
|
|
|
2009-12-16 04:19:58 -07:00
|
|
|
/**
|
|
|
|
* unpoison_memory - Unpoison a previously poisoned page
|
|
|
|
* @pfn: Page number of the to be unpoisoned page
|
|
|
|
*
|
|
|
|
* Software-unpoison a page that has been poisoned by
|
|
|
|
* memory_failure() earlier.
|
|
|
|
*
|
|
|
|
* This is only done on the software-level, so it only works
|
|
|
|
* for linux injected failures, not real hardware failures
|
|
|
|
*
|
|
|
|
* Returns 0 for success, otherwise -errno.
|
|
|
|
*/
|
|
|
|
int unpoison_memory(unsigned long pfn)
|
|
|
|
{
|
|
|
|
struct page *page;
|
|
|
|
struct page *p;
|
|
|
|
int freeit = 0;
|
2010-05-27 18:29:19 -06:00
|
|
|
unsigned int nr_pages;
|
2015-11-05 19:47:26 -07:00
|
|
|
static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL,
|
|
|
|
DEFAULT_RATELIMIT_BURST);
|
2009-12-16 04:19:58 -07:00
|
|
|
|
|
|
|
if (!pfn_valid(pfn))
|
|
|
|
return -ENXIO;
|
|
|
|
|
|
|
|
p = pfn_to_page(pfn);
|
|
|
|
page = compound_head(p);
|
|
|
|
|
|
|
|
if (!PageHWPoison(p)) {
|
2016-05-20 17:57:32 -06:00
|
|
|
unpoison_pr_info("Unpoison: Page was already unpoisoned %#lx\n",
|
2015-11-05 19:47:26 -07:00
|
|
|
pfn, &unpoison_rs);
|
2009-12-16 04:19:58 -07:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2015-09-08 16:03:29 -06:00
|
|
|
if (page_count(page) > 1) {
|
2016-05-20 17:57:32 -06:00
|
|
|
unpoison_pr_info("Unpoison: Someone grabs the hwpoison page %#lx\n",
|
2015-11-05 19:47:26 -07:00
|
|
|
pfn, &unpoison_rs);
|
2015-09-08 16:03:29 -06:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (page_mapped(page)) {
|
2016-05-20 17:57:32 -06:00
|
|
|
unpoison_pr_info("Unpoison: Someone maps the hwpoison page %#lx\n",
|
2015-11-05 19:47:26 -07:00
|
|
|
pfn, &unpoison_rs);
|
2015-09-08 16:03:29 -06:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (page_mapping(page)) {
|
2016-05-20 17:57:32 -06:00
|
|
|
unpoison_pr_info("Unpoison: the hwpoison page has non-NULL mapping %#lx\n",
|
2015-11-05 19:47:26 -07:00
|
|
|
pfn, &unpoison_rs);
|
2015-09-08 16:03:29 -06:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2013-09-11 15:22:53 -06:00
|
|
|
/*
|
|
|
|
* unpoison_memory() can encounter thp only when the thp is being
|
|
|
|
* worked by memory_failure() and the page lock is not held yet.
|
|
|
|
* In such case, we yield to memory_failure() and make unpoison fail.
|
|
|
|
*/
|
2013-09-30 14:45:22 -06:00
|
|
|
if (!PageHuge(page) && PageTransHuge(page)) {
|
2016-05-20 17:57:32 -06:00
|
|
|
unpoison_pr_info("Unpoison: Memory failure is now running on %#lx\n",
|
2015-11-05 19:47:26 -07:00
|
|
|
pfn, &unpoison_rs);
|
2015-06-24 17:56:48 -06:00
|
|
|
return 0;
|
2013-09-11 15:22:53 -06:00
|
|
|
}
|
|
|
|
|
2013-09-11 15:22:52 -06:00
|
|
|
nr_pages = 1 << compound_order(page);
|
2010-05-27 18:29:19 -06:00
|
|
|
|
2015-06-24 17:56:48 -06:00
|
|
|
if (!get_hwpoison_page(p)) {
|
2010-09-07 19:19:38 -06:00
|
|
|
/*
|
|
|
|
* Since HWPoisoned hugepage should have non-zero refcount,
|
|
|
|
* race between memory failure and unpoison seems to happen.
|
|
|
|
* In such case unpoison fails and memory failure runs
|
|
|
|
* to the end.
|
|
|
|
*/
|
|
|
|
if (PageHuge(page)) {
|
2016-05-20 17:57:32 -06:00
|
|
|
unpoison_pr_info("Unpoison: Memory failure is now running on free hugepage %#lx\n",
|
2015-11-05 19:47:26 -07:00
|
|
|
pfn, &unpoison_rs);
|
2010-09-07 19:19:38 -06:00
|
|
|
return 0;
|
|
|
|
}
|
2009-12-16 04:19:58 -07:00
|
|
|
if (TestClearPageHWPoison(p))
|
2015-09-08 16:03:24 -06:00
|
|
|
num_poisoned_pages_dec();
|
2016-05-20 17:57:32 -06:00
|
|
|
unpoison_pr_info("Unpoison: Software-unpoisoned free page %#lx\n",
|
2015-11-05 19:47:26 -07:00
|
|
|
pfn, &unpoison_rs);
|
2009-12-16 04:19:58 -07:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2011-03-10 00:52:07 -07:00
|
|
|
lock_page(page);
|
2009-12-16 04:19:58 -07:00
|
|
|
/*
|
|
|
|
* This test is racy because PG_hwpoison is set outside of page lock.
|
|
|
|
* That's acceptable because that won't trigger kernel panic. Instead,
|
|
|
|
* the PG_hwpoison page will be caught and isolated on the entrance to
|
|
|
|
* the free buddy page pool.
|
|
|
|
*/
|
2010-05-27 18:29:19 -06:00
|
|
|
if (TestClearPageHWPoison(page)) {
|
2016-05-20 17:57:32 -06:00
|
|
|
unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n",
|
2015-11-05 19:47:26 -07:00
|
|
|
pfn, &unpoison_rs);
|
2015-09-08 16:03:24 -06:00
|
|
|
num_poisoned_pages_sub(nr_pages);
|
2009-12-16 04:19:58 -07:00
|
|
|
freeit = 1;
|
2010-09-07 19:19:40 -06:00
|
|
|
if (PageHuge(page))
|
|
|
|
clear_page_hwpoison_huge_page(page);
|
2009-12-16 04:19:58 -07:00
|
|
|
}
|
|
|
|
unlock_page(page);
|
|
|
|
|
2015-09-08 16:03:21 -06:00
|
|
|
put_hwpoison_page(page);
|
mm/memory-failure.c: fix bug triggered by unpoisoning empty zero page
Injecting memory failure for page 0x19d0 at 0xb77d2000
MCE 0x19d0: non LRU page recovery: Ignored
MCE: Software-unpoisoned page 0x19d0
BUG: Bad page state in process bash pfn:019d0
page:f3461a00 count:0 mapcount:0 mapping: (null) index:0x0
page flags: 0x40000404(referenced|reserved)
Modules linked in: nfsd auth_rpcgss i915 nfs_acl nfs lockd video drm_kms_helper drm bnep rfcomm sunrpc bluetooth psmouse parport_pc ppdev lp serio_raw fscache parport gpio_ich lpc_ich mac_hid i2c_algo_bit tpm_tis wmi usb_storage hid_generic usbhid hid e1000e firewire_ohci firewire_core ahci ptp libahci pps_core crc_itu_t
CPU: 3 PID: 2123 Comm: bash Not tainted 3.11.0-rc6+ #12
Hardware name: LENOVO 7034DD7/ , BIOS 9HKT47AUS 01//2012
00000000 00000000 e9625ea0 c15ec49b f3461a00 e9625eb8 c15ea119 c17cbf18
ef084314 000019d0 f3461a00 e9625ed8 c110dc8a f3461a00 00000001 00000000
f3461a00 40000404 00000000 e9625ef8 c110dcc1 f3461a00 f3461a00 000019d0
Call Trace:
dump_stack+0x41/0x52
bad_page+0xcf/0xeb
free_pages_prepare+0x12a/0x140
free_hot_cold_page+0x21/0x110
__put_single_page+0x21/0x30
put_page+0x25/0x40
unpoison_memory+0x107/0x200
hwpoison_unpoison+0x20/0x30
simple_attr_write+0xb6/0xd0
vfs_write+0xa0/0x1b0
SyS_write+0x4f/0x90
sysenter_do_call+0x12/0x22
Disabling lock debugging due to kernel taint
Testcase:
#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <sys/mman.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <errno.h>
#define PAGES_TO_TEST 1
#define PAGE_SIZE 4096
int main(void)
{
char *mem;
mem = mmap(NULL, PAGES_TO_TEST * PAGE_SIZE,
PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
if (madvise(mem, PAGES_TO_TEST * PAGE_SIZE, MADV_HWPOISON) == -1)
return -1;
munmap(mem, PAGES_TO_TEST * PAGE_SIZE);
return 0;
}
There is one page reference count for default empty zero page,
madvise_hwpoison add another one by get_user_pages_fast. memory_hwpoison
reduce one page reference count since it's a non LRU page.
unpoison_memory release the last page reference count and free empty zero
page to buddy system which is not correct since empty zero page has
PG_reserved flag. This patch fix it by don't reduce the page reference
count under 1 against empty zero page.
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:23:01 -06:00
|
|
|
if (freeit && !(pfn == my_zero_pfn(0) && page_count(p) == 1))
|
2015-09-08 16:03:21 -06:00
|
|
|
put_hwpoison_page(page);
|
2009-12-16 04:19:58 -07:00
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(unpoison_memory);
|
2009-12-16 04:20:00 -07:00
|
|
|
|
|
|
|
static struct page *new_page(struct page *p, unsigned long private, int **x)
|
|
|
|
{
|
2009-12-16 04:20:01 -07:00
|
|
|
int nid = page_to_nid(p);
|
2010-09-07 19:19:39 -06:00
|
|
|
if (PageHuge(p))
|
|
|
|
return alloc_huge_page_node(page_hstate(compound_head(p)),
|
|
|
|
nid);
|
|
|
|
else
|
mm: rename alloc_pages_exact_node() to __alloc_pages_node()
alloc_pages_exact_node() was introduced in commit 6484eb3e2a81 ("page
allocator: do not check NUMA node ID when the caller knows the node is
valid") as an optimized variant of alloc_pages_node(), that doesn't
fallback to current node for nid == NUMA_NO_NODE. Unfortunately the
name of the function can easily suggest that the allocation is
restricted to the given node and fails otherwise. In truth, the node is
only preferred, unless __GFP_THISNODE is passed among the gfp flags.
The misleading name has lead to mistakes in the past, see for example
commits 5265047ac301 ("mm, thp: really limit transparent hugepage
allocation to local node") and b360edb43f8e ("mm, mempolicy:
migrate_to_node should only migrate to node").
Another issue with the name is that there's a family of
alloc_pages_exact*() functions where 'exact' means exact size (instead
of page order), which leads to more confusion.
To prevent further mistakes, this patch effectively renames
alloc_pages_exact_node() to __alloc_pages_node() to better convey that
it's an optimized variant of alloc_pages_node() not intended for general
usage. Both functions get described in comments.
It has been also considered to really provide a convenience function for
allocations restricted to a node, but the major opinion seems to be that
__GFP_THISNODE already provides that functionality and we shouldn't
duplicate the API needlessly. The number of users would be small
anyway.
Existing callers of alloc_pages_exact_node() are simply converted to
call __alloc_pages_node(), with the exception of sba_alloc_coherent()
which open-codes the check for NUMA_NO_NODE, so it is converted to use
alloc_pages_node() instead. This means it no longer performs some
VM_BUG_ON checks, and since the current check for nid in
alloc_pages_node() uses a 'nid < 0' comparison (which includes
NUMA_NO_NODE), it may hide wrong values which would be previously
exposed.
Both differences will be rectified by the next patch.
To sum up, this patch makes no functional changes, except temporarily
hiding potentially buggy callers. Restricting the checks in
alloc_pages_node() is left for the next patch which can in turn expose
more existing buggy callers.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Robin Holt <robinmholt@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Cliff Whickman <cpw@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08 16:03:50 -06:00
|
|
|
return __alloc_pages_node(nid, GFP_HIGHUSER_MOVABLE, 0);
|
2009-12-16 04:20:00 -07:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Safely get reference count of an arbitrary page.
|
|
|
|
* Returns 0 for a free page, -EIO for a zero refcount page
|
|
|
|
* that is not free, and 1 for any other page type.
|
|
|
|
* For 1 the page is returned with increased page count, otherwise not.
|
|
|
|
*/
|
2013-02-22 17:34:03 -07:00
|
|
|
static int __get_any_page(struct page *p, unsigned long pfn, int flags)
|
2009-12-16 04:20:00 -07:00
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
if (flags & MF_COUNT_INCREASED)
|
|
|
|
return 1;
|
|
|
|
|
2010-09-07 19:19:39 -06:00
|
|
|
/*
|
|
|
|
* When the target page is a free hugepage, just remove it
|
|
|
|
* from free hugepage list.
|
|
|
|
*/
|
2015-06-24 17:56:48 -06:00
|
|
|
if (!get_hwpoison_page(p)) {
|
2010-09-07 19:19:39 -06:00
|
|
|
if (PageHuge(p)) {
|
2012-05-29 16:06:16 -06:00
|
|
|
pr_info("%s: %#lx free huge page\n", __func__, pfn);
|
2013-02-22 17:34:03 -07:00
|
|
|
ret = 0;
|
2010-09-07 19:19:39 -06:00
|
|
|
} else if (is_free_buddy_page(p)) {
|
2012-05-29 16:06:16 -06:00
|
|
|
pr_info("%s: %#lx free buddy page\n", __func__, pfn);
|
2009-12-16 04:20:00 -07:00
|
|
|
ret = 0;
|
|
|
|
} else {
|
2012-05-29 16:06:16 -06:00
|
|
|
pr_info("%s: %#lx: unknown zero refcount page type %lx\n",
|
|
|
|
__func__, pfn, p->flags);
|
2009-12-16 04:20:00 -07:00
|
|
|
ret = -EIO;
|
|
|
|
}
|
|
|
|
} else {
|
|
|
|
/* Not a free page */
|
|
|
|
ret = 1;
|
|
|
|
}
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
2013-02-22 17:34:03 -07:00
|
|
|
static int get_any_page(struct page *page, unsigned long pfn, int flags)
|
|
|
|
{
|
|
|
|
int ret = __get_any_page(page, pfn, flags);
|
|
|
|
|
2017-02-24 15:57:35 -07:00
|
|
|
if (ret == 1 && !PageHuge(page) &&
|
|
|
|
!PageLRU(page) && !__PageMovable(page)) {
|
2013-02-22 17:34:03 -07:00
|
|
|
/*
|
|
|
|
* Try to free it.
|
|
|
|
*/
|
2015-09-08 16:03:21 -06:00
|
|
|
put_hwpoison_page(page);
|
2013-02-22 17:34:03 -07:00
|
|
|
shake_page(page, 1);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Did it turn free?
|
|
|
|
*/
|
|
|
|
ret = __get_any_page(page, pfn, 0);
|
2016-01-15 17:54:03 -07:00
|
|
|
if (ret == 1 && !PageLRU(page)) {
|
2015-08-14 16:34:56 -06:00
|
|
|
/* Drop page reference which is from __get_any_page() */
|
2015-09-08 16:03:21 -06:00
|
|
|
put_hwpoison_page(page);
|
2017-05-03 15:55:31 -06:00
|
|
|
pr_info("soft_offline: %#lx: unknown non LRU page type %lx (%pGp)\n",
|
|
|
|
pfn, page->flags, &page->flags);
|
2013-02-22 17:34:03 -07:00
|
|
|
return -EIO;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
2010-09-07 19:19:39 -06:00
|
|
|
static int soft_offline_huge_page(struct page *page, int flags)
|
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
unsigned long pfn = page_to_pfn(page);
|
|
|
|
struct page *hpage = compound_head(page);
|
2013-09-11 15:22:01 -06:00
|
|
|
LIST_HEAD(pagelist);
|
2010-09-07 19:19:39 -06:00
|
|
|
|
2013-02-22 17:34:03 -07:00
|
|
|
/*
|
|
|
|
* This double-check of PageHWPoison is to avoid the race with
|
|
|
|
* memory_failure(). See also comment in __soft_offline_page().
|
|
|
|
*/
|
|
|
|
lock_page(hpage);
|
2013-02-22 17:33:59 -07:00
|
|
|
if (PageHWPoison(hpage)) {
|
2013-02-22 17:34:03 -07:00
|
|
|
unlock_page(hpage);
|
2015-09-08 16:03:21 -06:00
|
|
|
put_hwpoison_page(hpage);
|
2013-02-22 17:33:59 -07:00
|
|
|
pr_info("soft offline: %#lx hugepage already poisoned\n", pfn);
|
2013-02-22 17:34:03 -07:00
|
|
|
return -EBUSY;
|
2013-02-22 17:33:59 -07:00
|
|
|
}
|
2013-02-22 17:34:03 -07:00
|
|
|
unlock_page(hpage);
|
2010-09-07 19:19:39 -06:00
|
|
|
|
2015-04-15 17:14:38 -06:00
|
|
|
ret = isolate_huge_page(hpage, &pagelist);
|
2015-08-14 16:34:59 -06:00
|
|
|
/*
|
|
|
|
* get_any_page() and isolate_huge_page() takes a refcount each,
|
|
|
|
* so need to drop one here.
|
|
|
|
*/
|
2015-09-08 16:03:21 -06:00
|
|
|
put_hwpoison_page(hpage);
|
2015-08-14 16:34:59 -06:00
|
|
|
if (!ret) {
|
2015-04-15 17:14:38 -06:00
|
|
|
pr_info("soft offline: %#lx hugepage failed to isolate\n", pfn);
|
|
|
|
return -EBUSY;
|
|
|
|
}
|
|
|
|
|
2014-06-04 17:08:25 -06:00
|
|
|
ret = migrate_pages(&pagelist, new_page, NULL, MPOL_MF_MOVE_ALL,
|
2013-09-11 15:22:01 -06:00
|
|
|
MIGRATE_SYNC, MR_MEMORY_FAILURE);
|
2010-09-07 19:19:39 -06:00
|
|
|
if (ret) {
|
2017-05-03 15:55:31 -06:00
|
|
|
pr_info("soft offline: %#lx: migration failed %d, type %lx (%pGp)\n",
|
|
|
|
pfn, ret, page->flags, &page->flags);
|
2013-09-11 15:22:01 -06:00
|
|
|
/*
|
|
|
|
* We know that soft_offline_huge_page() tries to migrate
|
|
|
|
* only one hugepage pointed to by hpage, so we need not
|
|
|
|
* run through the pagelist here.
|
|
|
|
*/
|
|
|
|
putback_active_hugepage(hpage);
|
|
|
|
if (ret > 0)
|
|
|
|
ret = -EIO;
|
2013-02-22 17:34:03 -07:00
|
|
|
} else {
|
2013-12-18 18:08:54 -07:00
|
|
|
/* overcommit hugetlb page will be freed to buddy */
|
|
|
|
if (PageHuge(page)) {
|
|
|
|
set_page_hwpoison_huge_page(hpage);
|
|
|
|
dequeue_hwpoisoned_huge_page(hpage);
|
2015-09-08 16:03:24 -06:00
|
|
|
num_poisoned_pages_add(1 << compound_order(hpage));
|
2013-12-18 18:08:54 -07:00
|
|
|
} else {
|
|
|
|
SetPageHWPoison(page);
|
2015-09-08 16:03:24 -06:00
|
|
|
num_poisoned_pages_inc();
|
2013-12-18 18:08:54 -07:00
|
|
|
}
|
2010-09-07 19:19:39 -06:00
|
|
|
}
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
2013-02-22 17:34:03 -07:00
|
|
|
static int __soft_offline_page(struct page *page, int flags)
|
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
unsigned long pfn = page_to_pfn(page);
|
2009-12-16 04:20:00 -07:00
|
|
|
|
|
|
|
/*
|
2013-02-22 17:34:03 -07:00
|
|
|
* Check PageHWPoison again inside page lock because PageHWPoison
|
|
|
|
* is set by memory_failure() outside page lock. Note that
|
|
|
|
* memory_failure() also double-checks PageHWPoison inside page lock,
|
|
|
|
* so there's no race between soft_offline_page() and memory_failure().
|
2009-12-16 04:20:00 -07:00
|
|
|
*/
|
2013-02-22 17:33:59 -07:00
|
|
|
lock_page(page);
|
|
|
|
wait_on_page_writeback(page);
|
2013-02-22 17:34:03 -07:00
|
|
|
if (PageHWPoison(page)) {
|
|
|
|
unlock_page(page);
|
2015-09-08 16:03:21 -06:00
|
|
|
put_hwpoison_page(page);
|
2013-02-22 17:34:03 -07:00
|
|
|
pr_info("soft offline: %#lx page already poisoned\n", pfn);
|
|
|
|
return -EBUSY;
|
|
|
|
}
|
2009-12-16 04:20:00 -07:00
|
|
|
/*
|
|
|
|
* Try to invalidate first. This should work for
|
|
|
|
* non dirty unmapped page cache pages.
|
|
|
|
*/
|
|
|
|
ret = invalidate_inode_page(page);
|
|
|
|
unlock_page(page);
|
|
|
|
/*
|
|
|
|
* RED-PEN would be better to keep it isolated here, but we
|
|
|
|
* would need to fix isolation locking first.
|
|
|
|
*/
|
|
|
|
if (ret == 1) {
|
2015-09-08 16:03:21 -06:00
|
|
|
put_hwpoison_page(page);
|
2010-09-27 15:31:30 -06:00
|
|
|
pr_info("soft_offline: %#lx: invalidated\n", pfn);
|
2013-02-22 17:34:03 -07:00
|
|
|
SetPageHWPoison(page);
|
2015-09-08 16:03:24 -06:00
|
|
|
num_poisoned_pages_inc();
|
2013-02-22 17:34:03 -07:00
|
|
|
return 0;
|
2009-12-16 04:20:00 -07:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Simple invalidation didn't work.
|
|
|
|
* Try to migrate to a new page instead. migrate.c
|
|
|
|
* handles a large number of cases for us.
|
|
|
|
*/
|
2017-02-24 15:57:35 -07:00
|
|
|
if (PageLRU(page))
|
|
|
|
ret = isolate_lru_page(page);
|
|
|
|
else
|
|
|
|
ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE);
|
2011-05-24 18:12:20 -06:00
|
|
|
/*
|
|
|
|
* Drop page reference which is came from get_any_page()
|
|
|
|
* successful isolate_lru_page() already took another one.
|
|
|
|
*/
|
2015-09-08 16:03:21 -06:00
|
|
|
put_hwpoison_page(page);
|
2009-12-16 04:20:00 -07:00
|
|
|
if (!ret) {
|
|
|
|
LIST_HEAD(pagelist);
|
2017-02-24 15:57:35 -07:00
|
|
|
/*
|
|
|
|
* After isolated lru page, the PageLRU will be cleared,
|
|
|
|
* so use !__PageMovable instead for LRU page's mapping
|
|
|
|
* cannot have PAGE_MAPPING_MOVABLE.
|
|
|
|
*/
|
|
|
|
if (!__PageMovable(page))
|
|
|
|
inc_node_page_state(page, NR_ISOLATED_ANON +
|
|
|
|
page_is_file_cache(page));
|
2009-12-16 04:20:00 -07:00
|
|
|
list_add(&page->lru, &pagelist);
|
2014-06-04 17:08:25 -06:00
|
|
|
ret = migrate_pages(&pagelist, new_page, NULL, MPOL_MF_MOVE_ALL,
|
2013-02-22 17:35:14 -07:00
|
|
|
MIGRATE_SYNC, MR_MEMORY_FAILURE);
|
2009-12-16 04:20:00 -07:00
|
|
|
if (ret) {
|
2017-02-24 15:57:35 -07:00
|
|
|
if (!list_empty(&pagelist))
|
|
|
|
putback_movable_pages(&pagelist);
|
2014-01-21 16:51:17 -07:00
|
|
|
|
2017-05-03 15:55:31 -06:00
|
|
|
pr_info("soft offline: %#lx: migration failed %d, type %lx (%pGp)\n",
|
|
|
|
pfn, ret, page->flags, &page->flags);
|
2009-12-16 04:20:00 -07:00
|
|
|
if (ret > 0)
|
|
|
|
ret = -EIO;
|
|
|
|
}
|
|
|
|
} else {
|
2017-05-03 15:55:31 -06:00
|
|
|
pr_info("soft offline: %#lx: isolation failed: %d, page count %d, type %lx (%pGp)\n",
|
|
|
|
pfn, ret, page_count(page), page->flags, &page->flags);
|
2009-12-16 04:20:00 -07:00
|
|
|
}
|
|
|
|
return ret;
|
|
|
|
}
|
2013-09-11 15:22:56 -06:00
|
|
|
|
2016-01-15 17:57:43 -07:00
|
|
|
static int soft_offline_in_use_page(struct page *page, int flags)
|
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
struct page *hpage = compound_head(page);
|
|
|
|
|
|
|
|
if (!PageHuge(page) && PageTransHuge(hpage)) {
|
|
|
|
lock_page(hpage);
|
2016-01-15 17:57:46 -07:00
|
|
|
if (!PageAnon(hpage) || unlikely(split_huge_page(hpage))) {
|
|
|
|
unlock_page(hpage);
|
|
|
|
if (!PageAnon(hpage))
|
|
|
|
pr_info("soft offline: %#lx: non anonymous thp\n", page_to_pfn(page));
|
|
|
|
else
|
|
|
|
pr_info("soft offline: %#lx: thp split failed\n", page_to_pfn(page));
|
|
|
|
put_hwpoison_page(hpage);
|
2016-01-15 17:57:43 -07:00
|
|
|
return -EBUSY;
|
|
|
|
}
|
2016-01-15 17:57:46 -07:00
|
|
|
unlock_page(hpage);
|
2016-01-15 17:57:43 -07:00
|
|
|
get_hwpoison_page(page);
|
|
|
|
put_hwpoison_page(hpage);
|
|
|
|
}
|
|
|
|
|
|
|
|
if (PageHuge(page))
|
|
|
|
ret = soft_offline_huge_page(page, flags);
|
|
|
|
else
|
|
|
|
ret = __soft_offline_page(page, flags);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void soft_offline_free_page(struct page *page)
|
|
|
|
{
|
|
|
|
if (PageHuge(page)) {
|
|
|
|
struct page *hpage = compound_head(page);
|
|
|
|
|
|
|
|
set_page_hwpoison_huge_page(hpage);
|
|
|
|
if (!dequeue_hwpoisoned_huge_page(hpage))
|
|
|
|
num_poisoned_pages_add(1 << compound_order(hpage));
|
|
|
|
} else {
|
|
|
|
if (!TestSetPageHWPoison(page))
|
|
|
|
num_poisoned_pages_inc();
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2013-09-11 15:22:56 -06:00
|
|
|
/**
|
|
|
|
* soft_offline_page - Soft offline a page.
|
|
|
|
* @page: page to offline
|
|
|
|
* @flags: flags. Same as memory_failure().
|
|
|
|
*
|
|
|
|
* Returns 0 on success, otherwise negated errno.
|
|
|
|
*
|
|
|
|
* Soft offline a page, by migration or invalidation,
|
|
|
|
* without killing anything. This is for the case when
|
|
|
|
* a page is not corrupted yet (so it's still valid to access),
|
|
|
|
* but has had a number of corrected errors and is better taken
|
|
|
|
* out.
|
|
|
|
*
|
|
|
|
* The actual policy on when to do that is maintained by
|
|
|
|
* user space.
|
|
|
|
*
|
|
|
|
* This should never impact any application or cause data loss,
|
|
|
|
* however it might take some time.
|
|
|
|
*
|
|
|
|
* This is not a 100% solution for all memory, but tries to be
|
|
|
|
* ``good enough'' for the majority of memory.
|
|
|
|
*/
|
|
|
|
int soft_offline_page(struct page *page, int flags)
|
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
unsigned long pfn = page_to_pfn(page);
|
|
|
|
|
|
|
|
if (PageHWPoison(page)) {
|
|
|
|
pr_info("soft offline: %#lx page already poisoned\n", pfn);
|
2015-09-08 16:03:13 -06:00
|
|
|
if (flags & MF_COUNT_INCREASED)
|
2015-09-08 16:03:21 -06:00
|
|
|
put_hwpoison_page(page);
|
2013-09-11 15:22:56 -06:00
|
|
|
return -EBUSY;
|
|
|
|
}
|
|
|
|
|
mem-hotplug: implement get/put_online_mems
kmem_cache_{create,destroy,shrink} need to get a stable value of
cpu/node online mask, because they init/destroy/access per-cpu/node
kmem_cache parts, which can be allocated or destroyed on cpu/mem
hotplug. To protect against cpu hotplug, these functions use
{get,put}_online_cpus. However, they do nothing to synchronize with
memory hotplug - taking the slab_mutex does not eliminate the
possibility of race as described in patch 2.
What we need there is something like get_online_cpus, but for memory.
We already have lock_memory_hotplug, which serves for the purpose, but
it's a bit of a hammer right now, because it's backed by a mutex. As a
result, it imposes some limitations to locking order, which are not
desirable, and can't be used just like get_online_cpus. That's why in
patch 1 I substitute it with get/put_online_mems, which work exactly
like get/put_online_cpus except they block not cpu, but memory hotplug.
[ v1 can be found at https://lkml.org/lkml/2014/4/6/68. I NAK'ed it by
myself, because it used an rw semaphore for get/put_online_mems,
making them dead lock prune. ]
This patch (of 2):
{un}lock_memory_hotplug, which is used to synchronize against memory
hotplug, is currently backed by a mutex, which makes it a bit of a
hammer - threads that only want to get a stable value of online nodes
mask won't be able to proceed concurrently. Also, it imposes some
strong locking ordering rules on it, which narrows down the set of its
usage scenarios.
This patch introduces get/put_online_mems, which are the same as
get/put_online_cpus, but for memory hotplug, i.e. executing a code
inside a get/put_online_mems section will guarantee a stable value of
online nodes, present pages, etc.
lock_memory_hotplug()/unlock_memory_hotplug() are removed altogether.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 17:07:18 -06:00
|
|
|
get_online_mems();
|
2013-09-11 15:22:56 -06:00
|
|
|
ret = get_any_page(page, pfn, flags);
|
mem-hotplug: implement get/put_online_mems
kmem_cache_{create,destroy,shrink} need to get a stable value of
cpu/node online mask, because they init/destroy/access per-cpu/node
kmem_cache parts, which can be allocated or destroyed on cpu/mem
hotplug. To protect against cpu hotplug, these functions use
{get,put}_online_cpus. However, they do nothing to synchronize with
memory hotplug - taking the slab_mutex does not eliminate the
possibility of race as described in patch 2.
What we need there is something like get_online_cpus, but for memory.
We already have lock_memory_hotplug, which serves for the purpose, but
it's a bit of a hammer right now, because it's backed by a mutex. As a
result, it imposes some limitations to locking order, which are not
desirable, and can't be used just like get_online_cpus. That's why in
patch 1 I substitute it with get/put_online_mems, which work exactly
like get/put_online_cpus except they block not cpu, but memory hotplug.
[ v1 can be found at https://lkml.org/lkml/2014/4/6/68. I NAK'ed it by
myself, because it used an rw semaphore for get/put_online_mems,
making them dead lock prune. ]
This patch (of 2):
{un}lock_memory_hotplug, which is used to synchronize against memory
hotplug, is currently backed by a mutex, which makes it a bit of a
hammer - threads that only want to get a stable value of online nodes
mask won't be able to proceed concurrently. Also, it imposes some
strong locking ordering rules on it, which narrows down the set of its
usage scenarios.
This patch introduces get/put_online_mems, which are the same as
get/put_online_cpus, but for memory hotplug, i.e. executing a code
inside a get/put_online_mems section will guarantee a stable value of
online nodes, present pages, etc.
lock_memory_hotplug()/unlock_memory_hotplug() are removed altogether.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 17:07:18 -06:00
|
|
|
put_online_mems();
|
2016-01-15 17:54:07 -07:00
|
|
|
|
2016-01-15 17:57:43 -07:00
|
|
|
if (ret > 0)
|
|
|
|
ret = soft_offline_in_use_page(page, flags);
|
|
|
|
else if (ret == 0)
|
|
|
|
soft_offline_free_page(page);
|
2016-01-15 17:54:07 -07:00
|
|
|
|
2013-09-11 15:22:56 -06:00
|
|
|
return ret;
|
|
|
|
}
|