linux_dsm_epyc7002/kernel/locking
Nicolai Hähnle 200b187440 locking/ww_mutex: Notify waiters that have to back off while adding tasks to wait list
While adding our task as a waiter, detect if another task should back off
because of us.

With this patch, we establish the invariant that the wait list contains
at most one (sleeping) waiter with ww_ctx->acquired > 0, and this waiter
will be the first waiter with a context.

Since only waiters with ww_ctx->acquired > 0 have to back off, this allows
us to be much more economical with wakeups.

Signed-off-by: Nicolai Hähnle <Nicolai.Haehnle@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maarten Lankhorst <dev@mblankhorst.nl>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dri-devel@lists.freedesktop.org
Link: http://lkml.kernel.org/r/1482346000-9927-8-git-send-email-nhaehnle@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14 11:14:43 +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 xfs: updates for 4.10-rc1 2016-12-14 21:35:31 -08:00
locktorture.c lcoking/locktorture: Simplify the torture_runnable computation 2016-04-28 10:57:51 +02:00
Makefile locking/lglock: Remove lglock implementation 2016-09-22 15:25:56 +02:00
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: Rework mutex::owner 2016-10-25 11:31:50 +02:00
mutex.c locking/ww_mutex: Notify waiters that have to back off while adding tasks to wait list 2017-01-14 11:14:43 +01:00
mutex.h locking/mutex: Rework mutex::owner 2016-10-25 11:31:50 +02:00
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: Explain locking rules for rt_mutex_proxy_unlock()/init_proxy_locked() 2016-12-02 11:13:57 +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 sched/core: Remove set_task_state() 2017-01-14 11:14:16 +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: Move the spinlock code to kernel/locking/ 2013-11-06 07:55:21 +01:00
spinlock.c locking/spinlocks: Remove the unused spin_lock_bh_nested() API 2017-01-12 09:33:39 +01:00