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locking/rwsem: Move owner setting code from rwsem.c to rwsem.h

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Move all the owner setting code closer to the rwsem-xadd fast paths
directly within rwsem.h file as well as in the slowpaths where owner
setting is done after acquring the lock. This will enable us to add
DEBUG_RWSEMS check in a later patch to make sure that read lock is
really acquired when rwsem_down_read_failed() returns, for instance.

Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
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>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20190404174320.22416-3-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Waiman Long
2019-04-04 13:43:11 -04:00
committed by Ingo Molnar
parent eecec78f77
commit c7580c1e84
3 changed files with 20 additions and 22 deletions
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6
kernel/locking/rwsem-xadd.c
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@@ -176,9 +176,8 @@ static void __rwsem_mark_wake(struct rw_semaphore *sem,
goto try_reader_grant;
}
/*
* It is not really necessary to set it to reader-owned here,
* but it gives the spinners an early indication that the
* readers now have the lock.
* Set it to reader-owned to give spinners an early
* indication that readers now have the lock.
*/
__rwsem_set_reader_owned(sem, waiter->task);
}
@@ -441,6 +440,7 @@ __rwsem_down_read_failed_common(struct rw_semaphore *sem, int state)
*/
if (atomic_long_read(&sem->count) >= 0) {
raw_spin_unlock_irq(&sem->wait_lock);
rwsem_set_reader_owned(sem);
return sem;
}
adjustment += RWSEM_WAITING_BIAS;