linux/kernel/locking
Chris Wilson 2b232e0c3b locking/ww_mutex: Replace cpu_relax() with cond_resched() for tests
When busy-spinning on a ww_mutex_trylock(), we depend upon the other
thread advancing and releasing the lock. This can not happen on a single
CPU unless we relinquish it:

  [ ] NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [kworker/0:1:18]
  ...
  [ ] Call Trace:
  [ ]  mutex_trylock()
  [ ]  test_mutex_work+0x31/0x56
  [ ]  process_one_work+0x1b4/0x2f9
  [ ]  worker_thread+0x1b0/0x27c
  [ ]  kthread+0xd1/0xd3
  [ ]  ret_from_fork+0x19/0x30

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: f2a5fec173 ("locking/ww_mutex: Begin kselftests for ww_mutex")
Link: http://lkml.kernel.org/r/20170228094011.2595-1-chris@chris-wilson.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 09:00:38 +01:00
..
lockdep_internals.h lockdep: Limit static allocations if PROVE_LOCKING_SMALL is defined 2016-11-18 11:33:19 -08:00
lockdep_proc.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
lockdep_states.h locking: Move the lockdep code to kernel/locking/ 2013-11-06 07:55:08 +01:00
lockdep.c Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-02-20 13:23:30 -08:00
locktorture.c Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-02-20 13:23:30 -08:00
Makefile locking/ww_mutex: Begin kselftests for ww_mutex 2017-01-14 11:37:14 +01:00
mcs_spinlock.h locking/core: Remove cpu_relax_lowlatency() users 2016-11-16 10:15:10 +01:00
mutex-debug.c locking/mutex: Rework mutex::owner 2016-10-25 11:31:50 +02:00
mutex-debug.h locking/mutex: Fix lockdep_assert_held() fail 2017-01-30 11:42:59 +01:00
mutex.c Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-02-20 13:23:30 -08:00
mutex.h locking/mutex: Fix lockdep_assert_held() fail 2017-01-30 11:42:59 +01:00
osq_lock.c locking/osq: Break out of spin-wait busy waiting loop for a preempted vCPU in osq_lock() 2016-11-22 12:48:10 +01:00
percpu-rwsem.c locking/percpu-rwsem: Replace waitqueue with rcuwait 2017-01-14 11:14:35 +01:00
qrwlock.c locking/core: Remove cpu_relax_lowlatency() users 2016-11-16 10:15:10 +01:00
qspinlock_paravirt.h locking/pvqspinlock: Don't wait if vCPU is preempted 2017-01-12 09:35:57 +01:00
qspinlock_stat.h don't open-code file_inode() 2016-12-04 18:29:28 -05:00
qspinlock.c locking/qspinlock: Use __this_cpu_dec() instead of full-blown this_cpu_dec() 2016-06-27 11:37:41 +02:00
rtmutex_common.h locking/rtmutex: Get rid of RT_MUTEX_OWNER_MASKALL 2016-12-02 11:13:57 +01:00
rtmutex-debug.c rtmutex: Cleanup deadlock detector debug logic 2014-06-21 22:05:30 +02:00
rtmutex-debug.h rtmutex: Cleanup deadlock detector debug logic 2014-06-21 22:05:30 +02:00
rtmutex.c locking/rtmutex: Flip unlikely() branch to likely() in __rt_mutex_slowlock() 2017-01-30 11:42:59 +01:00
rtmutex.h rtmutex: Cleanup deadlock detector debug logic 2014-06-21 22:05:30 +02:00
rwsem-spinlock.c sched/core: Remove set_task_state() 2017-01-14 11:14:16 +01:00
rwsem-xadd.c locking/rwsem: Reinit wake_q after use 2017-01-22 09:54:00 +01:00
rwsem.c locking/rwsem: Add reader-owned state to the owner field 2016-06-08 15:16:59 +02:00
rwsem.h locking/rwsem: Protect all writes to owner by WRITE_ONCE() 2016-06-08 15:16:59 +02:00
semaphore.c sched/core: Remove set_task_state() 2017-01-14 11:14:16 +01:00
spinlock_debug.c locking/spinlock/debug: Remove spinlock lockup detection code 2017-02-10 09:09:49 +01:00
spinlock.c locking/spinlocks: Remove the unused spin_lock_bh_nested() API 2017-01-12 09:33:39 +01:00
test-ww_mutex.c locking/ww_mutex: Replace cpu_relax() with cond_resched() for tests 2017-03-02 09:00:38 +01:00