linux/debian/patches/features/all/rt/fs-more-cpu-chill-fixups.patch

36 lines
1012 B
Diff

Subject: fs: namespace: Use cpu_chill() instead of cpu_relax()
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 07 Mar 2012 21:05:19 +0100
Retry loops on RT might loop forever when the modifying side was
preempted. Use cpu_chill() instead of cpu_relax() to let the system
make progress.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable-rt@vger.kernel.org
---
fs/namespace.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
Index: linux-3.2/fs/namespace.c
===================================================================
--- linux-3.2.orig/fs/namespace.c
+++ linux-3.2/fs/namespace.c
@@ -31,6 +31,7 @@
#include <linux/idr.h>
#include <linux/fs_struct.h>
#include <linux/fsnotify.h>
+#include <linux/delay.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
#include "pnode.h"
@@ -346,7 +347,7 @@ int mnt_want_write(struct vfsmount *mnt)
*/
while (mnt->mnt_flags & MNT_WRITE_HOLD) {
preempt_enable();
- cpu_relax();
+ cpu_chill();
preempt_disable();
}
/*