On Tue, Mar 06, 2012 at 01:39:42PM -0500, Vivek Goyal wrote: > On Tue, Mar 06, 2012 at 11:24:55AM -0500, Vivek Goyal wrote: > > On Tue, Mar 06, 2012 at 10:07:09AM -0500, Vivek Goyal wrote: > > > > [..] > > > > > > My system is hanging during reboot. Last message I see is "Detaching DM > > > devices" and nothing happens after that. I shall have to do some more > > > testing to figure out when did that start happening. > > > > Ok, git bisect shows that very first patch to drain the queue is culprit. > > > > 9e5b9f8 block: blk-throttle should be drained regardless of q->elevator > > > > Will do some more debugging. > > Hmm..., haven't reached to the bottom of the issue yet, but there is more > data. Ok, found it. Basically we have not initialized the q->queue_head during queue creation. Hence we end up thinking that q->queue_head is not empty. So following fixed the issue for me. I still don't understand the special cased code (q->queue_head is not empty but don't kick queue). block/blk-core.c | 1 + 1 file changed, 1 insertion(+) Index: tejun-misc/block/blk-core.c =================================================================== --- tejun-misc.orig/block/blk-core.c 2012-03-07 00:47:14.325852192 -0500 +++ tejun-misc/block/blk-core.c 2012-03-07 00:47:15.998853132 -0500 @@ -558,6 +558,7 @@ struct request_queue *blk_alloc_queue_no setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q); INIT_LIST_HEAD(&q->timeout_list); INIT_LIST_HEAD(&q->icq_list); + INIT_LIST_HEAD(&q->queue_head); #ifdef CONFIG_BLK_CGROUP INIT_LIST_HEAD(&q->blkg_list); #endif Thanks Vivek -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
