Daniel Vetter 2301002769 mutex: Add w/w mutex slowpath debugging ... Injects EDEADLK conditions at pseudo-random interval, with exponential backoff up to UINT_MAX (to ensure that every lock operation still completes in a reasonable time). This way we can test the wound slowpath even for ww mutex users where contention is never expected, and the ww deadlock avoidance algorithm is only needed for correctness against malicious userspace. An example would be protecting kernel modesetting properties, which thanks to single-threaded X isn't really expected to contend, ever. I've looked into using the CONFIG_FAULT_INJECTION infrastructure, but decided against it for two reasons: - EDEADLK handling is mandatory for ww mutex users and should never affect the outcome of a syscall. This is in contrast to -ENOMEM injection. So fine configurability isn't required. - The fault injection framework only allows to set a simple probability for failure. Now the probability that a ww mutex acquire stage with N locks will never complete (due to too many injected EDEADLK backoffs) is zero. But the expected number of ww_mutex_lock operations for the completely uncontended case would be O(exp(N)). The per-acuiqire ctx exponential backoff solution choosen here only results in O(log N) overhead due to injection and so O(log N * N) lock operations. This way we can fail with high probability (and so have good test coverage even for fancy backoff and lock acquisition paths) without running into patalogical cases. Note that EDEADLK will only ever be injected when we managed to acquire the lock. This prevents any behaviour changes for users which rely on the EALREADY semantics. Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Cc: rostedt@goodmis.org Cc: daniel@ffwll.ch Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20130620113117.4001.21681.stgit@patser Signed-off-by: Ingo Molnar <mingo@kernel.org>		2013-06-26 12:10:56 +02:00
..
cpu	idle: Enable interrupts in the weak arch_cpu_idle() implementation	2013-06-14 23:01:05 +02:00
debug	kgdb/sysrq: fix inconstistent help message of sysrq key	2013-04-30 17:04:10 -07:00
events	perf: Fix mmap() accounting hole	2013-06-19 12:44:13 +02:00
gcov	kernel/gcov: remove depends on CONFIG_EXPERIMENTAL	2013-01-11 11:39:33 -08:00
irq	irqdomain: document the simple domain first_irq	2013-06-08 21:15:09 +01:00
power	Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux	2013-05-02 19:40:34 -07:00
sched	Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2013-06-20 08:18:35 -10:00
time	tick: Remove useless timekeeping duty attribution to broadcast source	2013-05-31 15:58:32 +02:00
trace	tracing: Fix outputting formats of x86-tsc and counter when use trace_clock	2013-06-11 13:58:46 -04:00
.gitignore	kernel/hz.bc: ignore.	2013-04-22 07:09:06 -07:00
Kconfig.freezer	…
Kconfig.hz	…
Kconfig.locks	locking: Adjust spin lock inlining Kconfig options	2012-09-13 17:56:13 +02:00
Kconfig.preempt	…
Makefile	We get rid of the general module prefix confusion with a binary config option,	2013-05-05 10:58:06 -07:00
acct.c	fs: Fix hang with BSD accounting on frozen filesystem	2013-05-04 14:57:58 -04:00
async.c	async: rename and redefine async_func_ptr	2013-03-12 13:59:14 -07:00
audit.c	audit: wait_for_auditd() should use TASK_UNINTERRUPTIBLE	2013-06-12 16:29:45 -07:00
audit.h	Merge git://git.infradead.org/users/eparis/audit	2013-05-11 14:29:11 -07:00
audit_tree.c	kernel/audit_tree.c:audit_add_tree_rule(): protect `rule' from kill_rules()	2013-06-12 16:29:46 -07:00
audit_watch.c	audit: catch possible NULL audit buffers	2013-01-11 14:54:55 -08:00
auditfilter.c	auditfilter.c: fix kernel-doc warnings	2013-05-24 16:22:52 -07:00
auditsc.c	audit: Make testing for a valid loginuid explicit.	2013-05-07 22:27:15 -04:00
backtracetest.c	…
bounds.c	…
capability.c	Add file_ns_capable() helper function for open-time capability checking	2013-04-14 10:06:31 -07:00
cgroup.c	cgroup: warn about mismatching options of a new mount of an existing hierarchy	2013-05-29 07:59:39 +09:00
cgroup_freezer.c	cgroup: rename ->create/post_create/pre_destroy/destroy() to ->css_alloc/online/offline/free()	2012-11-19 08:13:38 -08:00
compat.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal	2013-05-01 07:21:43 -07:00
configs.c	proc: Supply PDE attribute setting accessor functions	2013-05-01 17:29:18 -04:00
context_tracking.c	Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2013-06-20 08:18:35 -10:00
cpu.c	CPU hotplug: provide a generic helper to disable/enable CPU hotplug	2013-06-12 16:29:44 -07:00
cpu_pm.c	…
cpuset.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2013-05-01 17:51:54 -07:00
crash_dump.c	…
cred.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2012-12-18 10:55:28 -08:00
delayacct.c	cputime: Use accessors to read task cputime stats	2013-01-27 19:23:31 +01:00
dma.c	…
elfcore.c	…
exec_domain.c	…
exit.c	move exit_task_namespaces() outside of exit_notify()	2013-06-15 05:39:08 +04:00
extable.c	extable: Flip the sorting message	2013-04-15 13:25:16 +02:00
fork.c	Merge branch 'for-3.10/drivers' of git://git.kernel.dk/linux-block	2013-05-08 11:51:05 -07:00
freezer.c	freezer: change ptrace_stop/do_signal_stop to use freezable_schedule()	2012-10-26 14:27:49 -07:00
futex.c	futex: fix kernel-doc notation and spello	2013-03-12 20:42:10 -07:00
futex_compat.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal	2013-02-23 18:50:11 -08:00
groups.c	…
hrtimer.c	Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2013-05-05 13:23:27 -07:00
hung_task.c	…
irq_work.c	Merge branch 'nohz/printk-v8' into irq/core	2013-02-05 00:48:46 +01:00
itimer.c	…
jump_label.c	…
kallsyms.c	kernel: kallsyms: memory override issue, need check destination buffer length	2013-04-15 15:17:26 +09:30
kcmp.c	kcmp: include linux/ptrace.h	2012-12-20 17:40:19 -08:00
kexec.c	kexec: Use min() and min_t() to simplify logic	2013-04-30 17:04:07 -07:00
kmod.c	usermodehelper: check subprocess_info->path != NULL	2013-05-16 12:01:11 -07:00
kprobes.c	kprobes: Fix to free gone and unused optprobes	2013-05-28 10:37:59 +02:00
ksysfs.c	Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2012-12-11 18:10:49 -08:00
kthread.c	kthread: implement probe_kthread_data()	2013-04-30 17:04:02 -07:00
latencytop.c	…
lglock.c	…
lockdep.c	Merge branch 'for-3.10/drivers' of git://git.kernel.dk/linux-block	2013-05-08 11:51:05 -07:00
lockdep_internals.h	…
lockdep_proc.c	lockdep: Use KSYM_NAME_LEN'ed buffer for __get_key_name()	2012-10-24 12:39:09 +02:00
lockdep_states.h	…
modsign_certificate.S	CONFIG_SYMBOL_PREFIX: cleanup.	2013-03-15 15:09:43 +10:30
modsign_pubkey.c	keys: use keyring_alloc() to create module signing keyring	2012-12-20 17:40:21 -08:00
module-internal.h	MODSIGN: Move the magic string to the end of a module and eliminate the search	2012-10-19 17:30:40 -07:00
module.c	kmemleak: No need for scanning specific module sections	2013-05-17 09:53:36 +01:00
module_signing.c	MODSIGN: Don't use enum-type bitfields in module signature info block	2012-12-05 11:27:24 +10:30
mutex-debug.c	…
mutex-debug.h	…
mutex.c	mutex: Add w/w mutex slowpath debugging	2013-06-26 12:10:56 +02:00
mutex.h	…
notifier.c	…
nsproxy.c	proc: Split the namespace stuff out into linux/proc_ns.h	2013-05-01 17:29:39 -04:00
padata.c	padata: use __this_cpu_read per-cpu helper	2012-12-06 17:16:23 +08:00
panic.c	dump_stack: implement arch-specific hardware description in task dumps	2013-04-30 17:04:02 -07:00
params.c	params: Fix potential memory leak in add_sysfs_param()	2013-03-18 11:40:21 +00:00
pid.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2013-05-01 17:51:54 -07:00
pid_namespace.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2013-05-01 17:51:54 -07:00
posix-cpu-timers.c	posix_timers: Fix pre-condition to stop the tick on full dynticks	2013-04-22 19:59:25 +02:00
posix-timers.c	posix-timers: Remove unused variable	2013-04-18 12:51:19 +02:00
printk.c	kmsg: honor dmesg_restrict sysctl on /dev/kmsg	2013-06-12 16:29:44 -07:00
profile.c	proc: Supply PDE attribute setting accessor functions	2013-05-01 17:29:18 -04:00
ptrace.c	aio: don't include aio.h in sched.h	2013-05-07 20:16:25 -07:00
range.c	range: Do not add new blank slot with add_range_with_merge	2013-06-18 11:32:10 -05:00
rcu.h	rcu: Provide RCU CPU stall warnings for tiny RCU	2013-01-28 22:06:21 -08:00
rcupdate.c	Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD	2013-01-28 22:25:21 -08:00
rcutiny.c	Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD	2013-01-28 22:25:21 -08:00
rcutiny_plugin.h	rcu: Provide RCU CPU stall warnings for tiny RCU	2013-01-28 22:06:21 -08:00
rcutorture.c	rcu: Allow rcutorture to be built at low optimization levels	2013-02-04 12:18:20 -08:00
rcutree.c	rcu: Fix deadlock with CPU hotplug, RCU GP init, and timer migration	2013-06-10 13:37:12 -07:00
rcutree.h	rcu: Don't call wakeup() with rcu_node structure ->lock held	2013-06-10 13:37:11 -07:00
rcutree_plugin.h	rcu: Don't allocate bootmem from rcu_init()	2013-05-15 10:41:12 -07:00
rcutree_trace.c	rcutrace: single_open() leaks	2013-05-05 00:16:35 -04:00
relay.c	Merge branch 'for-3.10/core' of git://git.kernel.dk/linux-block	2013-05-08 10:13:35 -07:00
res_counter.c	res_counter: return amount of charges after res_counter_uncharge()	2012-12-18 15:02:12 -08:00
resource.c	mem hotunplug: fix kfree() of bootmem memory	2013-04-29 15:54:40 -07:00
rtmutex-debug.c	sched/rt: Move rt specific bits into new header file	2013-02-07 20:51:08 +01:00
rtmutex-debug.h	…
rtmutex-tester.c	locking/rtmutex/tester: Set correct permissions on sysfs files	2013-04-10 14:48:37 +02:00
rtmutex.c	sched/rt: Move rt specific bits into new header file	2013-02-07 20:51:08 +01:00
rtmutex.h	…
rtmutex_common.h	…
rwsem.c	Revert "rw_semaphore: remove up/down_read_non_owner"	2013-03-23 15:53:52 -07:00
seccomp.c	seccomp: allow BPF_XOR based ALU instructions.	2013-03-26 11:07:19 +11:00
semaphore.c	semaphore: use `bool' type for semaphore_waiter's up	2013-04-30 17:04:08 -07:00
signal.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2013-05-01 14:08:52 -07:00
smp.c	kernel/smp.c: cleanups	2013-04-30 17:04:03 -07:00
smpboot.c	kthread: Prevent unpark race which puts threads on the wrong cpu	2013-04-12 14:18:43 +02:00
smpboot.h	…
softirq.c	Fix lockup related to stop_machine being stuck in __do_softirq.	2013-06-10 17:46:57 -07:00
spinlock.c	…
srcu.c	srcu: use ACCESS_ONCE() to access sp->completed in srcu_read_lock()	2013-02-07 15:19:36 -08:00
stacktrace.c	…
stop_machine.c	stop_machine: Mark per cpu stopper enabled early	2013-02-26 22:25:17 +01:00
sys.c	reboot: rigrate shutdown/reboot to boot cpu	2013-06-12 16:29:44 -07:00
sys_ni.c	unify compat fanotify_mark(2), switch to COMPAT_SYSCALL_DEFINE	2013-05-09 13:46:38 -04:00
sysctl.c	mm: replace hardcoded 3% with admin_reserve_pages knob	2013-04-29 15:54:36 -07:00
sysctl_binary.c	switch compat_sys_sysctl to COMPAT_SYSCALL_DEFINE	2013-05-09 14:53:20 -04:00
task_work.c	task_work: task_work_add() should not succeed after exit_task_work()	2012-09-13 16:47:34 +02:00
taskstats.c	taskstats: cgroupstats_user_cmd() may leak on error	2012-10-06 03:05:31 +09:00
test_kprobes.c	kernel/: rename random32() to prandom_u32()	2013-04-29 18:28:42 -07:00
time.c	timekeeping: Use inject_offset in warp_clock	2013-03-15 16:50:20 -07:00
timeconst.bc	kernel: Replace timeconst.pl with a bc script	2013-02-16 23:17:25 +01:00
timer.c	Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2013-05-15 14:05:17 -07:00
tracepoint.c	Tracing updates for Linux 3.10	2013-04-29 13:55:38 -07:00
tsacct.c	cputime: Use accessors to read task cputime stats	2013-01-27 19:23:31 +01:00
uid16.c	make SYSCALL_DEFINE<n>-generated wrappers do asmlinkage_protect	2013-03-03 22:58:33 -05:00
up.c	…
user-return-notifier.c	hlist: drop the node parameter from iterators	2013-02-27 19:10:24 -08:00
user.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2013-05-01 17:51:54 -07:00
user_namespace.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2013-05-01 17:51:54 -07:00
utsname.c	proc: Split the namespace stuff out into linux/proc_ns.h	2013-05-01 17:29:39 -04:00
utsname_sysctl.c	kernel/utsname_sysctl.c: put get/get_uts() into CONFIG_PROC_SYSCTL code block	2013-02-27 19:10:22 -08:00
wait.c	propagate name change to comments in kernel source	2012-12-06 10:39:54 +01:00
watchdog.c	watchdog: Add comments to explain the watchdog_disabled variable	2013-03-14 08:24:05 +01:00
workqueue.c	workqueue: don't perform NUMA-aware allocations on offline nodes in wq_numa_init()	2013-05-15 14:24:24 -07:00
workqueue_internal.h	workqueue: include workqueue info when printing debug dump of a worker task	2013-04-30 17:04:02 -07:00