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* [PATCH] cfq: fix IOPRIO_CLASS_IDLE accounting
@ 2007-11-04 19:32 Oleg Nesterov
  2007-11-05  7:57 ` Jens Axboe
  0 siblings, 1 reply; 2+ messages in thread
From: Oleg Nesterov @ 2007-11-04 19:32 UTC (permalink / raw)
  To: Andrew Morton, Jens Axboe; +Cc: Nick, Randy Dunlap, linux-kernel

(untested, needs an ack from maintainer)

Spotted by Nick <gentuu@gmail.com>, hopefully can explain the second trace in
http://bugzilla.kernel.org/show_bug.cgi?id=9180.

If ->async_idle_cfqq != NULL cfq_put_async_queues() puts it IOPRIO_BE_NR times
in a loop. Fix this.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>

--- cfq/block/cfq-iosched.c~	2007-08-09 19:59:26.000000000 +0400
+++ cfq/block/cfq-iosched.c	2007-11-04 22:23:42.000000000 +0300
@@ -2065,9 +2065,10 @@ static void cfq_put_async_queues(struct 
 			cfq_put_queue(cfqd->async_cfqq[0][i]);
 		if (cfqd->async_cfqq[1][i])
 			cfq_put_queue(cfqd->async_cfqq[1][i]);
-		if (cfqd->async_idle_cfqq)
-			cfq_put_queue(cfqd->async_idle_cfqq);
 	}
+
+	if (cfqd->async_idle_cfqq)
+		cfq_put_queue(cfqd->async_idle_cfqq);
 }
 
 static void cfq_exit_queue(elevator_t *e)


^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH] cfq: fix IOPRIO_CLASS_IDLE accounting
  2007-11-04 19:32 [PATCH] cfq: fix IOPRIO_CLASS_IDLE accounting Oleg Nesterov
@ 2007-11-05  7:57 ` Jens Axboe
  0 siblings, 0 replies; 2+ messages in thread
From: Jens Axboe @ 2007-11-05  7:57 UTC (permalink / raw)
  To: Oleg Nesterov; +Cc: Andrew Morton, Nick, Randy Dunlap, linux-kernel

On Sun, Nov 04 2007, Oleg Nesterov wrote:
> (untested, needs an ack from maintainer)
> 
> Spotted by Nick <gentuu@gmail.com>, hopefully can explain the second trace in
> http://bugzilla.kernel.org/show_bug.cgi?id=9180.
> 
> If ->async_idle_cfqq != NULL cfq_put_async_queues() puts it IOPRIO_BE_NR times
> in a loop. Fix this.

That's obviously buggy, thanks Oleg! Fix is indeed correct. I'll add it.

-- 
Jens Axboe


^ permalink raw reply	[flat|nested] 2+ messages in thread

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2007-11-04 19:32 [PATCH] cfq: fix IOPRIO_CLASS_IDLE accounting Oleg Nesterov
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