diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2012-12-20 18:28:26 +0100 |
---|---|---|
committer | Steven Rostedt <rostedt@rostedt.homelinux.com> | 2013-01-17 15:09:35 -0500 |
commit | 8957dbe8442067dbc9389119c34cce0c41fe4b76 (patch) | |
tree | c585f984cfabc014c082e6bb8826799d61e4e943 | |
parent | 31fc476aa365d57a96ba003e0d7861e5fe34965e (diff) |
block: Use cpu_chill() for retry loops
Retry loops on RT might loop forever when the modifying side was
preempted. Steven also observed a live lock when there was a
concurrent priority boosting going on.
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
-rw-r--r-- | block/blk-ioc.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/block/blk-ioc.c b/block/blk-ioc.c index fb95dd2f889a..6b542018ed1e 100644 --- a/block/blk-ioc.c +++ b/block/blk-ioc.c @@ -8,6 +8,7 @@ #include <linux/blkdev.h> #include <linux/bootmem.h> /* for max_pfn/max_low_pfn */ #include <linux/slab.h> +#include <linux/delay.h> #include "blk.h" @@ -110,7 +111,7 @@ static void ioc_release_fn(struct work_struct *work) spin_unlock(q->queue_lock); } else { spin_unlock_irqrestore(&ioc->lock, flags); - cpu_relax(); + cpu_chill(); spin_lock_irqsave_nested(&ioc->lock, flags, 1); } } @@ -188,7 +189,7 @@ retry: spin_unlock(icq->q->queue_lock); } else { spin_unlock_irqrestore(&ioc->lock, flags); - cpu_relax(); + cpu_chill(); goto retry; } } |