[dm-devel] [PATCH] dm: Update a source code comment

Bart Van Assche bvanassche at acm.org
Mon Dec 3 12:32:32 UTC 2012


Update a source code comment with the conclusions of the discussion
of the patch that introduced this comment (commit a8c32a5). See also
http://www.redhat.com/archives/dm-devel/2012-November/msg00003.html.

Signed-off-by: Bart Van Assche <bvanassche at acm.org>
Cc: Jens Axboe <axboe at kernel.dk>
Cc: Alasdair G Kergon <agk at redhat.com>
Cc: Jun'ichi Nomura <j-nomura at ce.jp.nec.com>
Cc: Tejun Heo <tj at kernel.org>
Cc: stable at vger.kernel.org
---
 drivers/md/dm.c |    7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 77e6eff..0ec0673 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -740,12 +740,7 @@ static void rq_completed(struct mapped_device *md, int rw, int run_queue)
 	if (!md_in_flight(md))
 		wake_up(&md->wait);
 
-	/*
-	 * Run this off this callpath, as drivers could invoke end_io while
-	 * inside their request_fn (and holding the queue lock). Calling
-	 * back into ->request_fn() could deadlock attempting to grab the
-	 * queue lock again.
-	 */
+	/* run queue asynchronously to minimize time spent in soft-IRQ ctxt */
 	if (run_queue)
 		blk_run_queue_async(md->queue);
 
-- 
1.7.10.4




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