aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/mutex-debug.c
Commit message (Collapse)AuthorAgeFilesLines
* mutex: implement adaptive spinningPeter Zijlstra2009-01-141-8/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change mutex contention behaviour such that it will sometimes busy wait on acquisition - moving its behaviour closer to that of spinlocks. This concept got ported to mainline from the -rt tree, where it was originally implemented for rtmutexes by Steven Rostedt, based on work by Gregory Haskins. Testing with Ingo's test-mutex application (http://lkml.org/lkml/2006/1/8/50) gave a 345% boost for VFS scalability on my testbox: # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 296604 # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 85870 The key criteria for the busy wait is that the lock owner has to be running on a (different) cpu. The idea is that as long as the owner is running, there is a fair chance it'll release the lock soon, and thus we'll be better off spinning instead of blocking/scheduling. Since regular mutexes (as opposed to rtmutexes) do not atomically track the owner, we add the owner in a non-atomic fashion and deal with the races in the slowpath. Furthermore, to ease the testing of the performance impact of this new code, there is means to disable this behaviour runtime (without having to reboot the system), when scheduler debugging is enabled (CONFIG_SCHED_DEBUG=y), by issuing the following command: # echo NO_OWNER_SPIN > /debug/sched_features This command re-enables spinning again (this is also the default): # echo OWNER_SPIN > /debug/sched_features Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* mutex-debug: check mutex magic before ownerJeremy Kerr2008-05-161-1/+1
| | | | | | | | | | | | | | Currently, the mutex debug code checks the lock->owner before lock->magic, so a corrupt mutex will most likely result in failing the owner check, rather than the magic check. This change to debug_mutex_unlock does the magic check first, so we have a better idea of what breaks. Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* kernel: remove fastcall in kernel/*Harvey Harrison2008-02-081-1/+1
| | | | | | | | [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] remove many unneeded #includes of sched.hTim Schmielau2007-02-141-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | After Al Viro (finally) succeeded in removing the sched.h #include in module.h recently, it makes sense again to remove other superfluous sched.h includes. There are quite a lot of files which include it but don't actually need anything defined in there. Presumably these includes were once needed for macros that used to live in sched.h, but moved to other header files in the course of cleaning it up. To ease the pain, this time I did not fiddle with any header files and only removed #includes from .c-files, which tend to cause less trouble. Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha, arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig, allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all configs in arch/arm/configs on arm. I also checked that no new warnings were introduced by the patch (actually, some warnings are removed that were emitted by unnecessarily included header files). Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] lockdep: show more details about self-test failuresIngo Molnar2006-12-071-0/+3
| | | | | | | | | Make the locking self-test failures (of 'FAILURE' type) easier to debug by printing more information. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Lockdep: add lockdep_set_class_and_subclass() and lockdep_set_subclass()Peter Zijlstra2006-10-111-1/+1
| | | | | | | | | | | | | This annotation makes it possible to assign a subclass on lock init. This annotation is meant to reduce the _nested() annotations by assigning a default subclass. One could do without this annotation and rely on lockdep_set_class() exclusively, but that would require a manual stack of struct lock_class_key objects. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
* [PATCH] lockdep: prove mutex locking correctnessIngo Molnar2006-07-031-1/+5
| | | | | | | | | Use the lock validator framework to prove mutex locking correctness. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] lockdep: better lock debuggingIngo Molnar2006-07-031-44/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Generic lock debugging: - generalized lock debugging framework. For example, a bug in one lock subsystem turns off debugging in all lock subsystems. - got rid of the caller address passing (__IP__/__IP_DECL__/etc.) from the mutex/rtmutex debugging code: it caused way too much prototype hackery, and lockdep will give the same information anyway. - ability to do silent tests - check lock freeing in vfree too. - more finegrained debugging options, to allow distributions to turn off more expensive debugging features. There's no separate 'held mutexes' list anymore - but there's a 'held locks' stack within lockdep, which unifies deadlock detection across all lock classes. (this is independent of the lockdep validation stuff - lockdep first checks whether we are holding a lock already) Here are the current debugging options: CONFIG_DEBUG_MUTEXES=y CONFIG_DEBUG_LOCK_ALLOC=y which do: config DEBUG_MUTEXES bool "Mutex debugging, basic checks" config DEBUG_LOCK_ALLOC bool "Detect incorrect freeing of live mutexes" Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] lockdep: remove mutex deadlock checking codeIngo Molnar2006-07-031-316/+0
| | | | | | | | | With the lock validator we detect mutex deadlocks (and more), the mutex deadlock checking code is both redundant and slower. So remove it. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] lockdep: rename DEBUG_WARN_ON()Ingo Molnar2006-07-031-15/+15
| | | | | | | | | Rename DEBUG_WARN_ON() to the less generic DEBUG_LOCKS_WARN_ON() name, so that it's clear that this is a lock-debugging internal mechanism. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] poison: add & use more constantsRandy Dunlap2006-06-271-2/+3
| | | | | | | | | | | | | | | | Add more poison values to include/linux/poison.h. It's not clear to me whether some others should be added or not, so I haven't added any of these: ./include/linux/libata.h:#define ATA_TAG_POISON 0xfafbfcfdU ./arch/ppc/8260_io/fcc_enet.c:1918: memset((char *)(&(immap->im_dprambase[(mem_addr+64)])), 0x88, 32); ./drivers/usb/mon/mon_text.c:429: memset(mem, 0xe5, sizeof(struct mon_event_text)); ./drivers/char/ftape/lowlevel/ftape-ctl.c:738: memset(ft_buffer[i]->address, 0xAA, FT_BUFF_SIZE); ./drivers/block/sx8.c:/* 0xf is just arbitrary, non-zero noise; this is sorta like poisoning */ Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] work around ppc64 bootup bug by making mutex-debugging save/restore irqsIngo Molnar2006-06-261-6/+6
| | | | | | | | | | | | | | It seems ppc64 wants to lock mutexes in early bootup code, with interrupts disabled, and they expect interrupts to stay disabled, else they crash. Work around this bug by making mutex debugging variants save/restore irq flags. Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fix/simplify mutex debugging codeDavid Woodhouse2006-01-111-2/+3
| | | | | | | | | | Let's switch mutex_debug_check_no_locks_freed() to take (addr, len) as arguments instead, since all its callers were just calculating the 'to' address for themselves anyway... (and sometimes doing so badly). Signed-off-by: David Woodhouse <dwmw2@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mutex: trivial whitespace cleanupsIngo Molnar2006-01-101-1/+0
| | | | | Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] remove unnecessary asm/mutex.h from kernel/mutex-debug.cIngo Molnar2006-01-101-2/+0
| | | | | | | | Remove unnecessary (and incorrect) inclusion of asm/mutex.h, pointed out by David Howells. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mutex subsystem, debugging codeIngo Molnar2006-01-091-0/+464
mutex implementation - add debugging code. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@infradead.org>
generated by cgit v1.1 at 2024-12-26 19:57:44 +0000