Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2993406AbbHHWPf (ORCPT ); Sat, 8 Aug 2015 18:15:35 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:36352 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2993057AbbHHWPc (ORCPT ); Sat, 8 Aug 2015 18:15:32 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mike Snitzer Subject: [PATCH 4.1 050/123] Revert "dm: only run the queue on completion if congested or no requests pending" Date: Sat, 8 Aug 2015 15:08:48 -0700 Message-Id: <20150808220719.683000701@linuxfoundation.org> X-Mailer: git-send-email 2.5.0 In-Reply-To: <20150808220717.771230091@linuxfoundation.org> References: <20150808220717.771230091@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1932 Lines: 61 4.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mike Snitzer commit 621739b00e16ca2d80411dc9b111cb15b91f3ba9 upstream. This reverts commit 9a0e609e3fd8a95c96629b9fbde6b8c5b9a1456a. (Resolved a conflict during revert due to commit bfebd1cdb4 that came after) This revert is motivated by a couple failure reports on request-based DM multipath testbeds: 1) Netapp reported that their multipath fault injection test under heavy IO load can stall longer than 300 seconds. 2) IBM reported elevated lock contention in their testbed (likely due to increased back pressure due to IO not being dispatched as quickly): https://www.redhat.com/archives/dm-devel/2015-July/msg00057.html Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1053,13 +1053,10 @@ static struct dm_rq_target_io *tio_from_ */ static void rq_completed(struct mapped_device *md, int rw, bool run_queue) { - int nr_requests_pending; - atomic_dec(&md->pending[rw]); /* nudge anyone waiting on suspend queue */ - nr_requests_pending = md_in_flight(md); - if (!nr_requests_pending) + if (!md_in_flight(md)) wake_up(&md->wait); /* @@ -1071,8 +1068,7 @@ static void rq_completed(struct mapped_d if (run_queue) { if (md->queue->mq_ops) blk_mq_run_hw_queues(md->queue, true); - else if (!nr_requests_pending || - (nr_requests_pending >= md->queue->nr_congestion_on)) + else blk_run_queue_async(md->queue); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/