Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751413AbaAMD0T (ORCPT ); Sun, 12 Jan 2014 22:26:19 -0500 Received: from numascale.com ([213.162.240.84]:57913 "EHLO numascale.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751362AbaAMD0N (ORCPT ); Sun, 12 Jan 2014 22:26:13 -0500 X-Greylist: delayed 2312 seconds by postgrey-1.27 at vger.kernel.org; Sun, 12 Jan 2014 22:26:13 EST Message-ID: <52D353C8.4000000@numascale.com> Date: Mon, 13 Jan 2014 10:47:36 +0800 From: Daniel J Blueman Organization: Numascale AS User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Waiman Long CC: "Paul E. McKenney" , Linux Kernel Subject: Re: [PATCH v8 4/4] qrwlock: Use smp_store_release() in write_unlock() Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - cpanel21.proisp.no X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - numascale.com X-Get-Message-Sender-Via: cpanel21.proisp.no: authenticated_id: daniel@numascale.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 > Reviewed-by: Paul E. McKenney > --- > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/