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Jens Axboe 7fcbbaf183 mm/filemap.c: avoid always dirtying mapping->flags on O_DIRECT
In some testing I ran today (some fio jobs that spread over two nodes),
we end up spending 40% of the time in filemap_check_errors().  That
smells fishy.  Looking further, this is basically what happens:

blkdev_aio_read()
    generic_file_aio_read()
        filemap_write_and_wait_range()
            if (!mapping->nr_pages)
                filemap_check_errors()

and filemap_check_errors() always attempts two test_and_clear_bit() on
the mapping flags, thus dirtying it for every single invocation.  The
patch below tests each of these bits before clearing them, avoiding this
issue.  In my test case (4-socket box), performance went from 1.7M IOPS
to 4.0M IOPS.

Signed-off-by: Jens Axboe <axboe@fb.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-23 09:37:29 -07:00
..
Kconfig parisc,metag: Do not hardcode maximum userspace stack size 2014-05-15 00:01:41 +01:00
Kconfig.debug mm: more intensive memory corruption debugging 2012-01-10 16:30:42 -08:00
Makefile Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
backing-dev.c bdi: avoid oops on device removal 2014-04-03 16:20:49 -07:00
balloon_compaction.c mm: print more details for bad_page() 2014-01-23 16:36:50 -08:00
bootmem.c mm/bootmem.c: remove unused local `map' 2013-11-13 12:09:09 +09:00
bounce.c block: Convert bio_for_each_segment() to bvec_iter 2013-11-23 22:33:49 -08:00
cleancache.c mm: dump page when hitting a VM_BUG_ON using VM_BUG_ON_PAGE 2014-01-23 16:36:50 -08:00
compaction.c mm/compaction: make isolate_freepages start at pageblock boundary 2014-05-06 13:04:59 -07:00
debug-pagealloc.c mm, x86: Remove debug_pagealloc_enabled 2011-12-06 09:24:07 +01:00
dmapool.c dmapool: make DMAPOOL_DEBUG detect corruption of free marker 2012-12-11 17:22:24 -08:00
early_ioremap.c mm: create generic early_ioremap() support 2014-04-07 16:36:15 -07:00
fadvise.c teach SYSCALL_DEFINE<n> how to deal with long long/unsigned long long 2013-03-03 22:46:22 -05:00
failslab.c switch debugfs to umode_t 2012-01-03 22:54:56 -05:00
filemap.c mm/filemap.c: avoid always dirtying mapping->flags on O_DIRECT 2014-05-23 09:37:29 -07:00
filemap_xip.c seqcount: Add lockdep functionality to seqcount/seqlock structures 2013-11-06 12:40:26 +01:00
fremap.c mm: fix bad rss-counter if remap_file_pages raced migration 2014-03-19 16:21:49 -07:00
frontswap.c frontswap: fix incorrect zeroing and allocation size for frontswap_map 2013-06-12 16:29:46 -07:00
highmem.c Some nice cleanups, and even a patch my wife did as a "live" demo for 2012-12-20 08:37:05 -08:00
huge_memory.c thp: close race between split and zap huge pages 2014-04-18 16:40:09 -07:00
hugetlb.c hugetlb: ensure hugepage access is denied if hugepages are not supported 2014-05-06 13:04:58 -07:00
hugetlb_cgroup.c cgroup: drop const from @buffer of cftype->write_string() 2014-03-19 10:23:54 -04:00
hwpoison-inject.c mm/hwpoison: add '#' to hwpoison_inject 2014-01-21 16:19:48 -08:00
init-mm.c atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
internal.h mm/readahead.c: inline ra_submit 2014-04-07 16:35:58 -07:00
interval_tree.c mm: add CONFIG_DEBUG_VM_RB build option 2012-10-09 16:22:42 +09:00
iov_iter.c take iov_iter stuff to mm/iov_iter.c 2014-04-01 23:19:30 -04:00
kmemcheck.c
kmemleak-test.c kmemleak: remove memset by using kzalloc 2011-01-27 18:31:51 +00:00
kmemleak.c mm: postpone the disabling of kmemleak early logging 2014-05-11 17:55:48 +09:00
ksm.c mm: close PageTail race 2014-03-04 07:55:47 -08:00
list_lru.c mm: keep page cache radix tree nodes in check 2014-04-03 16:21:01 -07:00
maccess.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
madvise.c mm/hwpoison: fix traversal of hugetlbfs pages to avoid printk flood 2013-09-30 14:31:02 -07:00
memblock.c mm/memblock.c: use PFN_PHYS() 2014-04-07 16:35:58 -07:00
memcontrol.c mm: filemap: update find_get_pages_tag() to deal with shadow entries 2014-05-06 13:04:59 -07:00
memory-failure.c hwpoison, hugetlb: lock_page/unlock_page does not match for handling a free hugepage 2014-05-23 09:37:29 -07:00
memory.c mm: split 'tlb_flush_mmu()' into tlb flushing and memory freeing parts 2014-04-25 16:05:40 -07:00
memory_hotplug.c mm/memory_hotplug.c: move register_memory_resource out of the lock_memory_hotplug 2014-01-23 16:36:52 -08:00
mempolicy.c mm, mempolicy: remove per-process flag 2014-04-07 16:35:54 -07:00
mempool.c mempool: add unlikely and likely hints 2014-04-07 16:35:55 -07:00
migrate.c mm: fix swapops.h:131 bug if remap_file_pages raced migration 2014-03-20 22:09:09 -07:00
mincore.c mm + fs: prepare for non-page entries in page cache radix trees 2014-04-03 16:21:00 -07:00
mlock.c mm: try_to_unmap_cluster() should lock_page() before mlocking 2014-04-07 16:35:57 -07:00
mm_init.c mm: bring back /sys/kernel/mm 2014-01-27 21:02:39 -08:00
mmap.c mm: per-thread vma caching 2014-04-07 16:35:53 -07:00
mmu_context.c sched/mm: call finish_arch_post_lock_switch in idle_task_exit and use_mm 2014-02-21 08:50:17 +01:00
mmu_notifier.c mm: audit/fix non-modular users of module_init in core code 2014-01-23 16:36:52 -08:00
mmzone.c mm: numa: Change page last {nid,pid} into {cpu,pid} 2013-10-09 14:47:45 +02:00
mprotect.c mm: move mmu notifier call from change_protection to change_pmd_range 2014-04-07 16:35:50 -07:00
mremap.c mm, thp: close race between mremap() and split_huge_page() 2014-05-11 17:55:48 +09:00
msync.c
nobootmem.c mm/nobootmem.c: mark function as static 2014-04-03 16:21:02 -07:00
nommu.c mm: fix 'ERROR: do not initialise globals to 0 or NULL' and coding style 2014-04-07 16:35:55 -07:00
oom_kill.c mm, oom: base root bonus on current usage 2014-01-30 16:56:56 -08:00
page-writeback.c mm/page-writeback.c: fix divide by zero in pos_ratio_polynom 2014-05-06 13:04:58 -07:00
page_alloc.c mm/page_alloc.c: change mm debug routines back to EXPORT_SYMBOL 2014-04-07 16:35:59 -07:00
page_cgroup.c mm/page_cgroup.c: mark functions as static 2014-04-03 16:21:02 -07:00
page_io.c Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
page_isolation.c mm: memory-hotplug: enable memory hotplug to handle hugepage 2013-09-11 15:57:48 -07:00
pagewalk.c mm/pagewalk.c: fix walk_page_range() access of wrong PTEs 2013-10-30 14:27:03 -07:00
percpu-km.c
percpu-vm.c mm: fix kernel-doc warnings 2012-06-20 14:39:36 -07:00
percpu.c percpu: make pcpu_alloc_chunk() use pcpu_mem_free() instead of kfree() 2014-04-14 16:18:06 -04:00
pgtable-generic.c mm: fix TLB flush race between migration, and change_protection_range 2013-12-18 19:04:51 -08:00
process_vm_access.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
quicklist.c mm: delete various needless include <linux/module.h> 2011-10-31 09:20:11 -04:00
readahead.c mm/readahead.c: inline ra_submit 2014-04-07 16:35:58 -07:00
rmap.c mm: try_to_unmap_cluster() should lock_page() before mlocking 2014-04-07 16:35:57 -07:00
shmem.c mm: Initialize error in shmem_file_aio_read() 2014-04-13 14:10:26 -07:00
slab.c slab: Fix off by one in object max number tests. 2014-05-05 20:38:49 -07:00
slab.h slub: use sysfs'es release mechanism for kmem_cache 2014-05-06 13:04:59 -07:00
slab_common.c slub: use sysfs'es release mechanism for kmem_cache 2014-05-06 13:04:59 -07:00
slob.c mm: slab/slub: use page->list consistently instead of page->lru 2014-04-11 10:06:06 +03:00
slub.c slub: use sysfs'es release mechanism for kmem_cache 2014-05-06 13:04:59 -07:00
sparse-vmemmap.c mm/sparse: use memblock apis for early memory allocations 2014-01-21 16:19:47 -08:00
sparse.c mm: use macros from compiler.h instead of __attribute__((...)) 2014-04-07 16:35:54 -07:00
swap.c mm: thrash detection-based file cache sizing 2014-04-03 16:21:01 -07:00
swap_state.c swap: add a simple detector for inappropriate swapin readahead 2014-02-06 13:48:51 -08:00
swapfile.c mm/swap: fix race on swap_info reuse between swapoff and swapon 2014-02-06 13:48:51 -08:00
truncate.c mm: filemap: update find_get_pages_tag() to deal with shadow entries 2014-05-06 13:04:59 -07:00
util.c nick kvfree() from apparmor 2014-05-06 14:02:53 -04:00
vmacache.c mm: don't pointlessly use BUG_ON() for sanity check 2014-04-28 14:24:09 -07:00
vmalloc.c mm/vmalloc.c: enhance vm_map_ram() comment 2014-04-07 16:35:55 -07:00
vmpressure.c arm, pm, vmpressure: add missing slab.h includes 2014-02-03 13:24:01 -05:00
vmscan.c revert "mm: vmscan: do not swap anon pages just because free+file is low" 2014-05-06 13:04:59 -07:00
vmstat.c CPU hotplug notifiers registration fixes for 3.15-rc1 2014-04-07 14:55:46 -07:00
workingset.c mm: keep page cache radix tree nodes in check 2014-04-03 16:21:01 -07:00
zbud.c mm/zbud: fix some trivial typos in comments 2013-09-11 15:57:35 -07:00
zsmalloc.c zsmalloc: Fix CPU hotplug callback registration 2014-03-20 13:43:45 +01:00
zswap.c Merge branch 'akpm' (incoming from Andrew) 2014-04-07 16:38:06 -07:00