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
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
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
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
Makefile
We get rid of the general module prefix confusion with a binary config option,
2013-05-05 10:58:06 -07:00
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
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