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From: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
To: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: arnd@arndb.de, waiman.long@hp.com, peterz@infradead.org,
	Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Subject: [PATCH] locking/qrwlock: fix write unlock issue in big endian
Date: Thu,  2 Jun 2016 18:09:08 +0800	[thread overview]
Message-ID: <1464862148-5672-1-git-send-email-xinhui.pan@linux.vnet.ibm.com> (raw)

strcut __qrwlock has different layout in big endian machine. we need set
the __qrwlock->wmode to NULL, and the address is not &lock->cnts in big
endian machine.

Do as what read unlock does. we are lucky that the __qrwlock->wmode's
val is _QW_LOCKED.

Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
---
 include/asm-generic/qrwlock.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/asm-generic/qrwlock.h b/include/asm-generic/qrwlock.h
index 54a8e65..eadd7a3 100644
--- a/include/asm-generic/qrwlock.h
+++ b/include/asm-generic/qrwlock.h
@@ -139,7 +139,7 @@ static inline void queued_read_unlock(struct qrwlock *lock)
  */
 static inline void queued_write_unlock(struct qrwlock *lock)
 {
-	smp_store_release((u8 *)&lock->cnts, 0);
+	(void)atomic_sub_return_release(_QW_LOCKED, &lock->cnts);
 }
 
 /*
-- 
1.9.1

             reply	other threads:[~2016-06-02 10:09 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-02 10:09 Pan Xinhui [this message]
2016-06-02 10:44 ` [PATCH] locking/qrwlock: fix write unlock issue in big endian Arnd Bergmann
2016-06-02 11:01   ` xinhui
2016-06-02 11:15     ` Peter Zijlstra
2016-06-03  7:20       ` xinhui
2016-06-02 11:02   ` Peter Zijlstra
2016-06-03  7:17     ` xinhui
2016-06-03  7:17     ` xinhui
     [not found]     ` <201606030718.u537FQg0009963@mx0a-001b2d01.pphosted.com>
2016-06-03 20:57       ` Waiman Long
2016-06-03 20:57         ` Waiman Long
2016-06-06  3:15         ` xinhui
2016-06-06  3:15         ` xinhui
2016-06-08  9:22 ` Will Deacon
2016-06-14  6:11   ` xinhui
2016-06-14 10:40     ` Will Deacon
2016-06-15  3:47       ` xinhui

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