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| author | Davidlohr Bueso <dave@stgolabs.net> | 2015-01-30 01:14:25 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-02-18 16:57:13 +0100 |
| commit | 7a215f89a0335582292ec6f3edaa3abd570da75a (patch) | |
| tree | e2f21b6e285b864eab87f5a13a1cbf91b2152eb4 /kernel/locking/mutex.c | |
| parent | 49e4b2bcf7b812e985e65b6c8a0255b1520a6e7e (diff) | |
| download | op-kernel-dev-7a215f89a0335582292ec6f3edaa3abd570da75a.zip op-kernel-dev-7a215f89a0335582292ec6f3edaa3abd570da75a.tar.gz | |
locking/rwsem: Set lock ownership ASAP
In order to optimize the spinning step, we need to set the lock
owner as soon as the lock is acquired; after a successful counter
cmpxchg operation, that is. This is particularly useful as rwsems
need to set the owner to nil for readers, so there is a greater
chance of falling out of the spinning. Currently we only set the
owner much later in the game, in the more generic level -- latency
can be specially bad when waiting for a node->next pointer when
releasing the osq in up_write calls.
As such, update the owner inside rwsem_try_write_lock (when the
lock is obtained after blocking) and rwsem_try_write_lock_unqueued
(when the lock is obtained while spinning). This requires creating
a new internal rwsem.h header to share the owner related calls.
Also cleanup some headers for mutex and rwsem.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Jason Low <jason.low2@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michel Lespinasse <walken@google.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Link: http://lkml.kernel.org/r/1422609267-15102-4-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/locking/mutex.c')
| -rw-r--r-- | kernel/locking/mutex.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index 59cd6c3..43bf25e 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -25,7 +25,7 @@ #include <linux/spinlock.h> #include <linux/interrupt.h> #include <linux/debug_locks.h> -#include "mcs_spinlock.h" +#include <linux/osq_lock.h> /* * In the DEBUG case we are using the "NULL fastpath" for mutexes, |
