From f4af3c3d077a004762aaad052049c809fd8c6f0c Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 12 Apr 2011 14:58:51 +0200 Subject: [PATCH 1/1] block: move queue run on unplug to kblockd There are worries that we are now consuming a lot more stack in some cases, since we potentially call into IO dispatch from schedule() or io_schedule(). We can reduce this problem by moving the running of the queue to kblockd, like the old plugging scheme did as well. This may or may not be a good idea from a performance perspective, depending on how many tasks have queue plugs running at the same time. For even the slightly contended case, doing just a single queue run from kblockd instead of multiple runs directly from the unpluggers will be faster. Signed-off-by: Jens Axboe --- block/blk-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/blk-core.c b/block/blk-core.c index c6eaa1f56466..36b1a7559f94 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -2665,7 +2665,7 @@ static int plug_rq_cmp(void *priv, struct list_head *a, struct list_head *b) static void queue_unplugged(struct request_queue *q, unsigned int depth) { trace_block_unplug_io(q, depth); - __blk_run_queue(q, false); + __blk_run_queue(q, true); if (q->unplugged_fn) q->unplugged_fn(q); -- 2.39.2