diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2012-12-20 17:28:26 (GMT) |
---|---|---|
committer | Scott Wood <scottwood@freescale.com> | 2014-04-10 00:19:45 (GMT) |
commit | e960551addbad2c36f32ed55d84566250fe46b6e (patch) | |
tree | fa0cd2f0580a78541e6ad21f9a2473313dae3998 /block | |
parent | e72903255fc2c93f1b60ecb9e019e768ef9893a1 (diff) | |
download | linux-fsl-qoriq-e960551addbad2c36f32ed55d84566250fe46b6e.tar.xz |
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
Diffstat (limited to 'block')
-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 46cd7bd..899d3e4 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; } } |