Current lockdep_map only caches one class with subclass == 0,
and looks up hash table of classes when subclass != 0.
It seems that this has no problem because the case of
subclass != 0 is rare. But locks of struct rq are
acquired with subclass == 1 when task migration is executed.
Task migration is high frequent event, so I modified lockdep
to cache subclasses.
I measured the score of perf bench sched messaging.
This patch has slightly but certain (order of milli seconds
or 10 milli seconds) effect when lots of tasks are running.
I'll show the result in the tail of this description.
NR_LOCKDEP_CACHING_CLASSES specifies how many classes can be
cached in the instances of lockdep_map.
I discussed with Peter Zijlstra in LinuxCon Japan about
this approach and he taught me that caching every subclasses(8)
is cleary waste of memory. So number of cached classes
should be configurable.
=== Score comparison of benchmarks ===
# "min" means best score, and "max" means worst score
for i in `seq 1 10`; do ./perf bench -f simple sched messaging; done
before: min: 0.565000, max: 0.583000, avg: 0.572500
after: min: 0.559000, max: 0.568000, avg: 0.563300
# with more processes
for i in `seq 1 10`; do ./perf bench -f simple sched messaging -g 40; done
before: min: 2.274000, max: 2.298000, avg: 2.286300
after: min: 2.242000, max: 2.270000, avg: 2.259700
Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1286269311-28336-2-git-send-email-mitake@dcl.info.waseda.ac.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When a driver module is unloaded and the last still open file is a raw
MIDI device, the card and its devices will be actually freed in the
snd_card_file_remove() call when that file is closed. Afterwards, rmidi
and rmidi->card point into freed memory, so the module pointer is likely
to be garbage.
(This was introduced by commit 9a1b64caac82aa02cb74587ffc798e6f42c6170a.)
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Reported-by: Krzysztof Foltman <wdev@foltman.com>
Cc: 2.6.30-2.6.35 <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Commit a7f8388e accidentally removed it... Al explains:
"Sorry, reordering breakage. In the signals tree here I have
static inline void sig_set_blocked(struct sigset_t *set)
...
and it's used all over the place (including quite a few places where
we currently have sigprocmask(SIG_SETMASK, set, NULL), which is what
it's equivalent to). With that done, m32r doesn't use _BLOCKABLE
anywhere, so it got removed. And that chunk got picked when I'd been
reordering the queue to pull the arch-specific fixes in front.
Sorry."
Signed-off-by: Kyle McMartin <kyle@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We currently have a kernel internal type called aligned_u64 which aligns
__u64's on 8 bytes boundaries even on systems which would normally align
them on 4 byte boundaries. This patch creates a new type __aligned_u64
which does the same thing but which is exposed to userspace rather than
being kernel internal.
[akpm: merge early as both the net and audit trees want this]
[akpm@linux-foundation.org: enhance the comment describing the reasons for using aligned_u64. Via Andreas and Andi.]
Based-on-patch-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Eric Paris <eparis@redhat.com>
Cc: Jan Engelhardt <jengelh@medozas.de>
Cc: David Miller <davem@davemloft.net>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a build error introduced by d6d1b650ae ("param: simple
locking for sysfs-writable charp parameters").
CC arch/um/kernel/trap.o
arch/um/drivers/hostaudio_kern.c: In function 'hostaudio_open':
arch/um/drivers/hostaudio_kern.c:204: error: '__param_dsp' undeclared (first use in this function)
arch/um/drivers/hostaudio_kern.c:204: error: (Each undeclared identifier is reported only once
arch/um/drivers/hostaudio_kern.c:204: error: for each function it appears in.)
arch/um/drivers/hostaudio_kern.c: In function 'hostmixer_open_mixdev':
arch/um/drivers/hostaudio_kern.c:265: error: '__param_mixer' undeclared (first use in this function)
arch/um/drivers/hostaudio_kern.c:272: error: '__param_dsp' undeclared (first use in this function)
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Tested-by: Toralf Förster <toralf.foerster@gmx.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix SDIO suspend/resume regression introduced by 4c2ef25fe0 "mmc: fix
all hangs related to mmc/sd card insert/removal during suspend/resume":
PM: Syncing filesystems ... done.
Freezing user space processes ... (elapsed 0.01 seconds) done.
Freezing remaining freezable tasks ... (elapsed 0.01 seconds) done.
Suspending console(s) (use no_console_suspend to debug)
pm_op(): platform_pm_suspend+0x0/0x5c returns -38
PM: Device pxa2xx-mci.0 failed to suspend: error -38
PM: Some devices failed to suspend
4c2ef25fe0 moved the card removal/insertion mechanism out of MMC's
suspend/resume path and into pm notifiers (mmc_pm_notify), and that
broke SDIO's expectation that mmc_suspend_host() will remove the card,
and squash the error, in case -ENOSYS is returned from the bus suspend
handler (mmc_sdio_suspend() in this case).
mmc_sdio_suspend() is using this whenever at least one of the card's SDIO
function drivers does not have suspend/resume handlers - in that case
it is agreed to force removal of the entire card.
This patch fixes this regression by trivially bringing back that part of
mmc_suspend_host(), which was removed by 4c2ef25fe0.
Reported-and-tested-by: Sven Neumann <s.neumann@raumfeld.com>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: <stable@kernel.org>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Chris Ball <cjb@laptop.org>
* 'upstream-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
HID: Add Cando touch screen 15.6-inch product id
HID: Add MULTI_INPUT quirk for turbox/mosart touchscreen
HID: hidraw, fix a NULL pointer dereference in hidraw_write
HID: hidraw, fix a NULL pointer dereference in hidraw_ioctl
Commit f81f2f7c (ubd: drop unnecessary rq->sector manipulation)
dropped request->sector manipulation in preparation for global request
handling cleanup; unfortunately, it incorrectly assumed that the
updated sector wasn't being used.
ubd tries to issue as many requests as possible to io_thread. When
issuing fails due to memory pressure or other reasons, the device is
put on the restart list and issuing stops. On IO completion, devices
on the restart list are scanned and IO issuing is restarted.
ubd issues IOs sg-by-sg and issuing can be stopped in the middle of a
request, so each device on the restart queue needs to remember where
to restart in its current request. ubd needs to keep track of the
issue position itself because,
* blk_rq_pos(req) is now updated by the block layer to keep track of
_completion_ position.
* Multiple io_req's for the current request may be in flight, so it's
difficult to tell where blk_rq_pos(req) currently is.
Add ubd->rq_pos to keep track of the issue position and use it to
correctly restart io_req issue.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Richard Weinberger <richard@nod.at>
Tested-by: Richard Weinberger <richard@nod.at>
Tested-by: Chris Frey <cdfrey@foursquare.net>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Tony Luck reports that the addition of the access_ok() check in commit
0eead9ab41 ("Don't dump task struct in a.out core-dumps") broke the
ia64 compile due to missing the necessary header file includes.
Rather than add yet another include (<asm/unistd.h>) to make everything
happy, just uninline the silly core dump helper functions and move the
bodies to fs/exec.c where they make a lot more sense.
dump_seek() in particular was too big to be an inline function anyway,
and none of them are in any way performance-critical. And we really
don't need to mess up our include file headers more than they already
are.
Reported-and-tested-by: Tony Luck <tony.luck@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
ehea: Fix a checksum issue on the receive path
net: allow FEC driver to use fixed PHY support
tg3: restore rx_dropped accounting
b44: fix carrier detection on bind
net: clear heap allocations for privileged ethtool actions
NET: wimax, fix use after free
ATM: iphase, remove sleep-inside-atomic
ATM: mpc, fix use after free
ATM: solos-pci, remove use after free
net/fec: carrier off initially to avoid root mount failure
r8169: use device model DMA API
r8169: allocate with GFP_KERNEL flag when able to sleep
akiphie points out that a.out core-dumps have that odd task struct
dumping that was never used and was never really a good idea (it goes
back into the mists of history, probably the original core-dumping
code). Just remove it.
Also do the access_ok() check on dump_write(). It probably doesn't
matter (since normal filesystems all seem to do it anyway), but he
points out that it's normally done by the VFS layer, so ...
[ I suspect that we should possibly do "vfs_write()" instead of
calling ->write directly. That also does the whole fsnotify and write
statistics thing, which may or may not be a good idea. ]
And just to be anal, do this all for the x86-64 32-bit a.out emulation
code too, even though it's not enabled (and won't currently even
compile)
Reported-by: akiphie <akiphie@lavabit.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The race is described as follows:
CPU X CPU Y
remove_hrtimer
// state & QUEUED == 0
timer->state = CALLBACK
unlock timer base
timer->f(n) //very long
hrtimer_start
lock timer base
remove_hrtimer // no effect
hrtimer_enqueue
timer->state = CALLBACK |
QUEUED
unlock timer base
hrtimer_start
lock timer base
remove_hrtimer
mode = INACTIVE
// CALLBACK bit lost!
switch_hrtimer_base
CALLBACK bit not set:
timer->base
changes to a
different CPU.
lock this CPU's timer base
The bug was introduced with commit ca109491f (hrtimer: removing all ur
callback modes) in 2.6.29
[ tglx: Feed new state via local variable and add a comment. ]
Signed-off-by: Salman Qazi <sqazi@google.com>
Cc: akpm@linux-foundation.org
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20101012142351.8485.21823.stgit@dungbeetle.mtv.corp.google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org
Hitoshi Mitake
Ingo Molnar
Linus Torvalds
Clemens Ladisch
Kyle McMartin
Eric Paris
FUJITA Tomonori
Eric Dumazet
Ohad Ben-Cohen
Tejun Heo
Salman Qazi