Impact: standardize IO on cached ops
On modern CPUs it is almost always a bad idea to use non-temporal stores,
as the regression in this commit has shown it:
30d697f: x86: fix performance regression in write() syscall
The kernel simply has no good information about whether using non-temporal
stores is a good idea or not - and trying to add heuristics only increases
complexity and inserts fragility.
The regression on cached write()s took very long to be found - over two
years. So dont take any chances and let the hardware decide how it makes
use of its caches.
The only exception is drivers/gpu/drm/i915/i915_gem.c: there were we are
absolutely sure that another entity (the GPU) will pick up the dirty
data immediately and that the CPU will not touch that data before the
GPU will.
Also, keep the _nocache() primitives to make it easier for people to
experiment with these details. There may be more clear-cut cases where
non-cached copies can be used, outside of filemap.c.
Cc: Salman Qazi <sqazi@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There was a theoretical possibility to a race between arming a page in
post_kmmio_handler() and disarming the page in
release_kmmio_fault_page():
cpu0 cpu1
------------------------------------------------------------------
mmiotrace shutdown
enter release_kmmio_fault_page
fault on the page
disarm the page
disarm the page
handle the MMIO access
re-arm the page
put the page on release list
remove_kmmio_fault_pages()
fault on the page
page not known to mmiotrace
fall back to do_page_fault()
*KABOOM*
(This scenario also shows the double disarm case which is allowed.)
Fixed by acquiring kmmio_lock in post_kmmio_handler() and checking
if the page is being released from mmiotrace.
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Cc: Stuart Bennett <stuart@freedesktop.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Upgrade some kmmio.c debug messages to warnings.
Allow secondary faults on probed pages to fall through, and only log
secondary faults that are not due to non-present pages.
Patch edited by Pekka Paalanen.
Signed-off-by: Stuart Bennett <stuart@freedesktop.org>
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
From 36772dcb6ffbbb68254cbfc379a103acd2fbfefc Mon Sep 17 00:00:00 2001
From: Pekka Paalanen <pq@iki.fi>
Date: Sat, 28 Feb 2009 21:34:59 +0200
Split set_page_presence() in kmmio.c into two more functions set_pmd_presence()
and set_pte_presence(). Purely code reorganization, no functional changes.
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Cc: Stuart Bennett <stuart@freedesktop.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
From baa99e2b32449ec7bf147c234adfa444caecac8a Mon Sep 17 00:00:00 2001
From: Pekka Paalanen <pq@iki.fi>
Date: Sun, 22 Feb 2009 20:02:43 +0200
Blindly setting _PAGE_PRESENT in disarm_kmmio_fault_page() overlooks the
possibility, that the page was not present when it was armed.
Make arm_kmmio_fault_page() store the previous page presence in struct
kmmio_fault_page and use it on disarm.
This patch was originally written by Stuart Bennett, but Pekka Paalanen
rewrote it a little different.
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Cc: Stuart Bennett <stuart@freedesktop.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Print a full warning once, if arming or disarming a page fails.
Also, if initial arming fails, do not handle the page further. This
avoids the possibility of a page failing to arm and then later claiming
to have handled any fault on that page.
WARN_ONCE added by Pekka Paalanen.
Signed-off-by: Stuart Bennett <stuart@freedesktop.org>
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Apparently pages far into an ioremapped region might not actually be
mapped during ioremap(). Add an optional read test to try to trigger a
multiply faulting MMIO access. Also add more messages to the kernel log
to help debugging.
This patch is based on a patch suggested by
Stuart Bennett <stuart@freedesktop.org>
who discovered bugs in mmiotrace related to normal kernel space faults.
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Cc: Stuart Bennett <stuart@freedesktop.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Check the read values against the written values in the MMIO read/write
test. This test shows if the given MMIO test area really works as
memory, which is a prerequisite for a successful mmiotrace test.
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Cc: Stuart Bennett <stuart@freedesktop.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Some Toshiba laptops have another ALC268 codec on slot#3 that conflicts
with the primary codec. The codec#3 is for the digital I/O, and should
be fixed by the driver, but it'd need a bunch of changes.
So, let's fix the probe problem temporarily by setting the default
probe_mask value.
Reference: kernel bugzilla #12735http://bugzilla.kernel.org/show_bug.cgi?id=12735
Tested-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The Motorola MOTOMAGX phones (Z6, E8, Zn5 so far) are providing
combined ACM/BLAN USB configuration. Since it has Vendor Specific
class, the corresponding drivers (cdc-acm, zaurus) can't find it just
by interface info. This patch adds usb id so the zaurus driver can
properly handle this combined device.
Signed-off-by: Dmitriy Taychenachev <dimichxp@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make usbnet_get_link() fall back to ethtool_op_get_link() instead of
defaulting to 1.
This makes usbnet_get_link return valid results without the need for a
driver specific check_connect or mii ops as long as the driver calls
netif_carrier_{on,off}() as appropriate. cdc_ether is an example of
such a driver.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current implementation of carrier detect in veth is broken.
It reports the link is down until both sides of the veth pair
are administatively up and then forever after it reports link up.
So fix veth so that it only reports link up when both interfaces
of the pair are administratively up.
Signed-off-by: Eric Biederman <ebiederm@aristanetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The Ericsson F3507g wireless broadband module provides a CDC Ethernet
compliant interface, but identifies it as a "Mobile Direct Line" CDC
subclass, thereby preventing the CDC Ethernet class driver from picking
it up. This patch adds the device id to cdc_ether.c as a workaround.
Ericsson has provided a "class" driver for this device:
http://kerneltrap.org/mailarchive/linux-net/2008/10/28/3832094
But closer inspection of that driver reveals that it adds little more
than duplication of code from cdc_ether.c. See also
http://marc.info/?l=linux-usb&m=123334979706403&w=2
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is 2nd attempt to implement the initialization/reading of MAC address
from EEPROM. The first used PCI's VPD and there were some problems, some
devices are not able to read EEPROM content by VPD. The 2nd one uses direct
access to EEPROM through bit-banging interface and my testing results seem
to be much better.
I tested 5 systems each with different Realtek NICs and I didn't find any
problem. AFAIK Francois's NICs also works fine.
Original description:
This fixes the problem when MAC address is set by ifconfig or by
ip link commands and this address is stored in the device after
reboot. The power-off is needed to get right MAC address.
This is problem when Xen daemon is running because it renames the device
name from ethX to pethX and sets its MAC address to FE:FF:FF:FF:FF:FF.
After reboot the device is still using FE:FF:FF:FF:FF:FF.
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rick McNeal from LSI identified a panic in selinux_netlbl_inode_permission()
caused by a certain sequence of SUNRPC operations. The problem appears to be
due to the lack of NULL pointer checking in the function; this patch adds the
pointer checks so the function will exit safely in the cases where the socket
is not completely initialized.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
This reverts commit 17581ad812.
Sitsofe Wheeler reported that /dev/dri/card0 is MIA on his EeePC 900
and bisected it to this commit.
Graphics card is an i915 in an EeePC 900:
00:02.0 VGA compatible controller [0300]:
Intel Corporation Mobile 915GM/GMS/910GML
Express Graphics Controller [8086:2592] (rev 04)
( Most likely the ioremap() of the driver failed and hence the card
did not initialize. )
Reported-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Bisected-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There's conflicting assumptions in shifting, the caller assumes
that dupsack results in S'ed skbs (or a part of it) for sure but
never gave a hint to tcp_sacktag_one when dsack is actually in
use. Thus DSACK retrans_out -= pcount was not taken and the
counter became out of sync. Remove obstacle from that information
flow to get DSACKs accounted in tcp_sacktag_one as expected.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Tested-by: Denys Fedoryshchenko <denys@visp.net.lb>
Signed-off-by: David S. Miller <davem@davemloft.net>
The DCB netlink interface is required for building the userspace tools
available at e1000.sourceforge.net
Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1) add an include for <linux/types.h>
2) change dcbmsg.dcb_family from unsigned char to __u8 to be more
consistent with use of kernel types
Signed-off-by: Chris Leech <christopher.leech@intel.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The netpoll entry checks are required to ensure that we don't
receive normal packets when invoked via netpoll. Unfortunately
it only ever worked for the netif_receive_skb/netif_rx entry
points. The VLAN (and subsequently GRO) entry point didn't
have the check and therefore can trigger all sorts of weird
problems.
This patch adds the netpoll check to all entry points.
I'm still uneasy with receiving at all under netpoll (which
apparently is only used by the out-of-tree kdump code). The
reason is it is perfectly legal to receive all data including
headers into highmem if netpoll is off, but if you try to do
that with netpoll on and someone gets a printk in an IRQ handler
you're going to get a nice BUG_ON.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Impact: fix new breakages introduced by previous fix
Commit c132937556 tried to clean up
bootmem arch wrapper but it wasn't quite correct. Before the commit,
the followings were broken.
* Low level interface functions prefixed with __ ignored arch
preference.
* reserve_bootmem(...) can't be mapped into
reserve_bootmem_node(NODE_DATA(0)->bdata, ...) because the node is
not preference here. The region specified MUST fall into the
specified region; otherwise, it will panic.
After the commit,
* If allocation fails for the arch preferred node, it should fallback
to whatever is available. Instead, it simply failed allocation.
There are too many internal details to allow generic wrapping and
still keep things simple for archs. Plus, all that arch wants is a
way to prefer certain node over another.
This patch drops the generic wrapping around alloc_bootmem_core() and
add alloc_bootmem_core() instead. If necessary, arch can define
bootmem_arch_referred_node() macro or function which takes all
allocation information and returns the preferred node. bootmem
generic code will always try the preferred node first and then
fallback to other nodes as usual.
Breakages noted and changes reviewed by Johannes Weiner.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Impact: remove compile warning
Mark local variable map_end in pcpu_populate_chunk() with
uninitialized_var(). The variable is always used in tandem with
map_start and guaranteed to be initialized before use but gcc doesn't
understand that.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Ingo Molnar <mingo@elte.hu>
Impact: unification
show_cpuinfo_core is identical for 32 and 64 bit and can be unified,
and CONFIG_X86_HT inherently depends on CONFIG_X86_SMP.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Some Logitech mice react to the magic knock like Elantech touchpad would.
This leads to those mice being misdetected as Elantech touchpads. Add a
version query to elantech_detect() to distinguish the two.
[dtor@mail.ru:
- lower severity of some messages - when we are not sure yet if
device is Elantech or not not responding to knock is not an error.
]
Signed-off-by: Arjan Opmeer <arjan@opmeer.net>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
When resuming from suspend newer Synaptics touchpads do not recover
correctly. Analysis of the resume sequence as applied in Linux was
compared to that of other operating systems. This indicated that the
other OSs were resetting the mouse before attempting to detect it (for
all Synaptics touchpads, old and new). Applying this same modification
fixes these newer Synaptics touchpads and brings the driver into line
with common OS reset behaviour.
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Commit ec42d4481e broke usbtouchscreen for
some eGalax/EETI devices that claim to be HID, but are not.
Devices confirmed to be real HID have the class set to HID and the protocol
set to 'mouse'. Some have HID class but protocol set to 'none'. Those are
not HID and should be driven by usbtouchscreen.
Fix the device ignoring macro by adding match for the protocol too.
Signed-off-by: Daniel Ritz <daniel.ritz@gmx.ch>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This patch utilizes the TRACE_EVENT_FORMAT macro to enable the C style
faster tracing for the irq subsystem trace points.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
This patch utilizes the TRACE_EVENT_FORMAT macro to enable the C style
faster tracing for the sched subsystem trace points.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
This patch adds the interface to enable the C style trace points.
In the directory /debugfs/tracing/events/subsystem/event
We now have three files:
enable : values 0 or 1 to enable or disable the trace event.
available_types: values 'raw' and 'printf' which indicate the tracing
types available for the trace point. If a developer does not
use the TRACE_EVENT_FORMAT macro and just uses the TRACE_FORMAT
macro, then only 'printf' will be available. This file is
read only.
type: values 'raw' or 'printf'. This indicates which type of tracing
is active for that trace point. 'printf' is the default and
if 'raw' is not available, this file is read only.
# echo raw > /debug/tracing/events/sched/sched_wakeup/type
# echo 1 > /debug/tracing/events/sched/sched_wakeup/enable
Will enable the C style tracing for the sched_wakeup trace point.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: cleanup
Add missing __user annotation to the parameter of get_sigframe().
Also change cast type to void __user * of *fpstate.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: lower overhead tracing
The current event tracer can automatically pick up trace points
that are registered with the TRACE_FORMAT macro. But it required
a printf format string and parsing. Although, this adds the ability
to get guaranteed information like task names and such, it took
a hit in overhead processing. This processing can add about 500-1000
nanoseconds overhead, but in some cases that too is considered
too much and we want to shave off as much from this overhead as
possible.
Tom Zanussi recently posted tracing patches to lkml that are based
on a nice idea about capturing the data via C structs using
STRUCT_ENTER, STRUCT_EXIT type of macros.
I liked that method very much, but did not like the implementation
that required a developer to add data/code in several disjoint
locations.
This patch extends the event_tracer macros to do a similar "raw C"
approach that Tom Zanussi did. But instead of having the developers
needing to tweak a bunch of code all over the place, they can do it
all in one macro - preferably placed near the code that it is
tracing. That makes it much more likely that tracepoints will be
maintained on an ongoing basis by the code they modify.
The new macro TRACE_EVENT_FORMAT is created for this approach. (Note,
a developer may still utilize the more low level DECLARE_TRACE macros
if they don't care about getting their traces automatically in the event
tracer.)
They can also use the existing TRACE_FORMAT if they don't need to code
the tracepoint in C, but just want to use the convenience of printf.
So if the developer wants to "hardwire" a tracepoint in the fastest
possible way, and wants to acquire their data via a user space utility
in a raw binary format, or wants to see it in the trace output but not
sacrifice any performance, then they can implement the faster but
more complex TRACE_EVENT_FORMAT macro.
Here's what usage looks like:
TRACE_EVENT_FORMAT(name,
TPPROTO(proto),
TPARGS(args),
TPFMT(fmt, fmt_args),
TRACE_STUCT(
TRACE_FIELD(type1, item1, assign1)
TRACE_FIELD(type2, item2, assign2)
[...]
),
TPRAWFMT(raw_fmt)
);
Note name, proto, args, and fmt, are all identical to what TRACE_FORMAT
uses.
name: is the unique identifier of the trace point
proto: The proto type that the trace point uses
args: the args in the proto type
fmt: printf format to use with the event printf tracer
fmt_args: the printf argments to match fmt
TRACE_STRUCT starts the ability to create a structure.
Each item in the structure is defined with a TRACE_FIELD
TRACE_FIELD(type, item, assign)
type: the C type of item.
item: the name of the item in the stucture
assign: what to assign the item in the trace point callback
raw_fmt is a way to pretty print the struct. It must match
the order of the items are added in TRACE_STUCT
An example of this would be:
TRACE_EVENT_FORMAT(sched_wakeup,
TPPROTO(struct rq *rq, struct task_struct *p, int success),
TPARGS(rq, p, success),
TPFMT("task %s:%d %s",
p->comm, p->pid, success?"succeeded":"failed"),
TRACE_STRUCT(
TRACE_FIELD(pid_t, pid, p->pid)
TRACE_FIELD(int, success, success)
),
TPRAWFMT("task %d success=%d")
);
This creates us a unique struct of:
struct {
pid_t pid;
int success;
};
And the way the call back would assign these values would be:
entry->pid = p->pid;
entry->success = success;
The nice part about this is that the creation of the assignent is done
via macro magic in the event tracer. Once the TRACE_EVENT_FORMAT is
created, the developer will then have a faster method to record
into the ring buffer. They do not need to worry about the tracer itself.
The developer would only need to touch the files in include/trace/*.h
Again, I would like to give special thanks to Tom Zanussi for this
nice idea.
Idea-from: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Right now all tracers must manage their own trace buffers. This was
to enforce tracers to be independent in case we finally decide to
allow each tracer to have their own trace buffer.
But now we are adding event tracing that writes to the current tracer's
buffer. This adds an interface to allow events to write to the current
tracer buffer without having to manage its own. Since event tracing
has no "tracer", and is just a way to hook into any other tracer.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
This patch makes the event files, set_event and available_events
aware of the subsystem.
Now you can enable an entire subsystem with:
echo 'irq:*' > set_event
Note: the '*' is not needed.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
If a trace point header defines TRACE_SYSTEM, then it will add the
following trace points into that event system.
If include/trace/irq_event_types.h has:
#define TRACE_SYSTEM irq
at the top and
#undef TRACE_SYSTEM
at the bottom, then a directory "irq" will be created in the
/debug/tracing/events directory. Inside that directory will contain the
two trace points that are defined in include/trace/irq_event_types.h.
Only adding the above to irq and not to sched, we get:
# ls /debug/tracing/events/
irq sched_process_exit sched_signal_send sched_wakeup_new
sched_kthread_stop sched_process_fork sched_switch
sched_kthread_stop_ret sched_process_free sched_wait_task
sched_migrate_task sched_process_wait sched_wakeup
# ls /debug/tracing/events/irq
irq_handler_entry irq_handler_exit
If we add #define TRACE_SYSTEM sched to the trace/sched_event_types.h
then the rest of the trace events will be put in a sched directory
within the events directory.
I've been playing with this idea of the subsystem for a while, but
recently Tom Zanussi posted some patches to lkml that included this
method. Tom's approach was clean and got me to finally put some effort
to clean up the event trace points.
Thanks to Tom Zanussi for demonstrating how nice the subsystem
method is.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
