From: Joe Korty <joe.korty@ccur.com>
To: dhowells@redhat.com, akpm@osdl.org
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH] volatile may be needed in rwsem
Date: Tue, 27 Jan 2004 14:11:55 -0500 [thread overview]
Message-ID: <20040127191155.GA12128@tsunami.ccur.com> (raw)
'flags' should be declared volatile as rwsem_down_failed_common() spins
waiting for this to change. Untested.
Against 2.6.1.
diff -Nua 2.6/lib/rwsem-spinlock.c.0 2.6/lib/rwsem-spinlock.c
--- 2.6/lib/rwsem-spinlock.c.0 2004-01-27 14:03:46.000000000 -0500
+++ 2.6/lib/rwsem-spinlock.c 2004-01-27 14:03:38.000000000 -0500
@@ -12,7 +12,7 @@
struct rwsem_waiter {
struct list_head list;
struct task_struct *task;
- unsigned int flags;
+ volatile unsigned int flags;
#define RWSEM_WAITING_FOR_READ 0x00000001
#define RWSEM_WAITING_FOR_WRITE 0x00000002
};
diff -Nua 2.6/lib/rwsem.c.0 2.6/lib/rwsem.c
--- 2.6/lib/rwsem.c.0 2004-01-27 14:03:46.000000000 -0500
+++ 2.6/lib/rwsem.c 2004-01-27 14:03:19.000000000 -0500
@@ -10,7 +10,7 @@
struct rwsem_waiter {
struct list_head list;
struct task_struct *task;
- unsigned int flags;
+ volatile unsigned int flags;
#define RWSEM_WAITING_FOR_READ 0x00000001
#define RWSEM_WAITING_FOR_WRITE 0x00000002
};
next reply other threads:[~2004-01-27 19:12 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-01-27 19:11 Joe Korty [this message]
2004-01-27 19:19 ` [PATCH] volatile may be needed in rwsem David Howells
2004-01-27 19:43 ` Joe Korty
2004-01-27 20:23 ` Paulo Marques
2004-01-27 20:20 ` Christian Borntraeger
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