Jens Axboe [jens.axboe@xxxxxxxxxx] wrote: > On Mon, Nov 24 2008, malahal@xxxxxxxxxx wrote: > > Stephen Rothwell [sfr@xxxxxxxxxxxxxxxx] wrote: > > > > The block timer code calls del_timer(), should it call del_timer_sync()? > > > > It is possible although unlikely that you are hitting del_timer_sync vs > > > > del_timer problem in the block timeout code. Can only be seen on SMP > > > > systems though! > > > > > > Is this still a problem in next-20081121? In that tree, the block commit > > > "block: leave the request timeout timer running even on an empty list" > > > was changed to add this: > > > > > > diff --git a/block/blk-core.c b/block/blk-core.c > > > index 04267d6..44f547c 100644 > > > --- a/block/blk-core.c > > > +++ b/block/blk-core.c > > > @@ -391,6 +391,7 @@ EXPORT_SYMBOL(blk_stop_queue); > > > void blk_sync_queue(struct request_queue *q) > > > { > > > del_timer_sync(&q->unplug_timer); > > > + del_timer_sync(&q->timeout); > > > kblockd_flush_work(&q->unplug_work); > > > } > > > EXPORT_SYMBOL(blk_sync_queue); > > > > I was looking at the Linux tree. Clearly same problem doesn't exist with > > the above commit! I wonder why kblockd_flush_work() is called after the > > del_timer_sync(). It makes sense to cancel the work and then shutdown > > the timer(s). I doubt if you are running into this problem though. > > If the kernel tested doesn't include the above fix, it'll surely go > boom. Can someone verify that this is the case? Just looked, next-20081119 doesn't have the above fix. It is included in next-20081120. Also note that the above fix is only partially copied, there is other part that removed deleting the timer when there are no outstanding requests. --Malahal. -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html