30 lines
933 B
Diff
30 lines
933 B
Diff
Subject: timer-fd: Prevent live lock
|
|
From: Thomas Gleixner <tglx@linutronix.de>
|
|
Date: Wed, 25 Jan 2012 11:08:40 +0100
|
|
|
|
If hrtimer_try_to_cancel() requires a retry, then depending on the
|
|
priority setting te retry loop might prevent timer callback completion
|
|
on RT. Prevent that by waiting for completion on RT, no change for a
|
|
non RT kernel.
|
|
|
|
Reported-by: Sankara Muthukrishnan <sankara.m@gmail.com>
|
|
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
|
|
Cc: stable-rt@vger.kernel.org
|
|
---
|
|
fs/timerfd.c | 2 +-
|
|
1 file changed, 1 insertion(+), 1 deletion(-)
|
|
|
|
Index: linux-3.2/fs/timerfd.c
|
|
===================================================================
|
|
--- linux-3.2.orig/fs/timerfd.c
|
|
+++ linux-3.2/fs/timerfd.c
|
|
@@ -313,7 +313,7 @@ SYSCALL_DEFINE4(timerfd_settime, int, uf
|
|
if (hrtimer_try_to_cancel(&ctx->tmr) >= 0)
|
|
break;
|
|
spin_unlock_irq(&ctx->wqh.lock);
|
|
- cpu_relax();
|
|
+ hrtimer_wait_for_timer(&ctx->tmr);
|
|
}
|
|
|
|
/*
|