Messages in this thread | | | Date | Mon, 13 Jan 2014 10:47:36 +0800 | From | Daniel J Blueman <> | Subject | Re: [PATCH v8 4/4] qrwlock: Use smp_store_release() in write_unlock() |
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On Thursday, 9 January 2014 01:10:03 UTC+8, Waiman Long wrote: > This patch modifies the queue_write_unlock() function to use the > new smp_store_release() function in another pending patch. It also > removes the temporary implementation of smp_load_acquire() and > smp_store_release() function in qrwlock.c. > > This patch should only be merged if PeterZ's linux-arch patch patch > was merged. > > Signed-off-by: Waiman Long <Waiman.Long@hp.com> > Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> > --- > include/asm-generic/qrwlock.h | 4 +--- > kernel/locking/qrwlock.c | 34 ---------------------------------- > 2 files changed, 1 insertions(+), 37 deletions(-) > > diff --git a/include/asm-generic/qrwlock.h b/include/asm-generic/qrwlock.h > index 2b9a7b4..4d4bd04 100644 > --- a/include/asm-generic/qrwlock.h > +++ b/include/asm-generic/qrwlock.h > @@ -179,9 +179,7 @@ static inline void queue_write_unlock(struct qrwlock *lock) > /* > * Make sure that none of the critical section will be leaked out. > */ > - smp_mb__before_clear_bit(); > - ACCESS_ONCE(lock->cnts.writer) = 0; > - smp_mb__after_clear_bit(); > + smp_store_release(&lock->cnts.writer, 0)
This will fail compilation, so probably needs further testing with Peter's load_acquire/store_release barrier patches.
Thanks, Daniel -- Daniel J Blueman Principal Software Engineer, Numascale
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