From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 062AEC2BB1D for ; Tue, 7 Apr 2020 10:27:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D17E52074B for ; Tue, 7 Apr 2020 10:27:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586255249; bh=VG7Z96ZUZlKYwd0TaRLpdkJIVqF3gxuR9xzR4g0qwd4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JhMcQYnqGBEffI/5h/1F2wd+iAZjCD7dAKGo4lBGNw3F9t+lm3gN3gDjf1Cqa8xFV XFUSDw/StYSP7XLFzQ+xZ4a2iOOgKkS7XZgwKV1aUbiBFffTIg99qJVX6wW8r14+ua 5mVHHrl7fAuiNrIl6wmbFdhdhd5yT8CzC0GkCpa8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728497AbgDGK12 (ORCPT ); Tue, 7 Apr 2020 06:27:28 -0400 Received: from mail.kernel.org ([198.145.29.99]:39460 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728375AbgDGK1I (ORCPT ); Tue, 7 Apr 2020 06:27:08 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C884A2074F; Tue, 7 Apr 2020 10:27:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586255227; bh=VG7Z96ZUZlKYwd0TaRLpdkJIVqF3gxuR9xzR4g0qwd4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pozIDK5lf/8aUBf27rokPXeKSl6tGFZf6BXWTBJelm1BRXkIxiQK01/QDohVnKxQN 0fBn7Og2AtVp5IueHZwmpQhQqUbZ0bsHMSsYzPhWMhq7oErAHM9lAa/VjFzzWl5E7h 8/6THeBczfPwVQHHFP8NfjNXdv3JdEm8sDAku3gY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andreas Gruenbacher , Barry Marson , Mike Snitzer Subject: [PATCH 5.6 27/29] Revert "dm: always call blk_queue_split() in dm_process_bio()" Date: Tue, 7 Apr 2020 12:22:24 +0200 Message-Id: <20200407101455.421449589@linuxfoundation.org> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200407101452.046058399@linuxfoundation.org> References: <20200407101452.046058399@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mike Snitzer commit 120c9257f5f19e5d1e87efcbb5531b7cd81b7d74 upstream. This reverts commit effd58c95f277744f75d6e08819ac859dbcbd351. blk_queue_split() is causing excessive IO splitting -- because blk_max_size_offset() depends on 'chunk_sectors' limit being set and if it isn't (as is the case for DM targets!) it falls back to splitting on a 'max_sectors' boundary regardless of offset. "Fix" this by reverting back to _not_ using blk_queue_split() in dm_process_bio() for normal IO (reads and writes). Long-term fix is still TBD but it should focus on training blk_max_size_offset() to call into a DM provided hook (to call DM's max_io_len()). Test results from simple misaligned IO test on 4-way dm-striped device with chunksize of 128K and stripesize of 512K: xfs_io -d -c 'pread -b 2m 224s 4072s' /dev/mapper/stripe_dev before this revert: 253,0 21 1 0.000000000 2206 Q R 224 + 4072 [xfs_io] 253,0 21 2 0.000008267 2206 X R 224 / 480 [xfs_io] 253,0 21 3 0.000010530 2206 X R 224 / 256 [xfs_io] 253,0 21 4 0.000027022 2206 X R 480 / 736 [xfs_io] 253,0 21 5 0.000028751 2206 X R 480 / 512 [xfs_io] 253,0 21 6 0.000033323 2206 X R 736 / 992 [xfs_io] 253,0 21 7 0.000035130 2206 X R 736 / 768 [xfs_io] 253,0 21 8 0.000039146 2206 X R 992 / 1248 [xfs_io] 253,0 21 9 0.000040734 2206 X R 992 / 1024 [xfs_io] 253,0 21 10 0.000044694 2206 X R 1248 / 1504 [xfs_io] 253,0 21 11 0.000046422 2206 X R 1248 / 1280 [xfs_io] 253,0 21 12 0.000050376 2206 X R 1504 / 1760 [xfs_io] 253,0 21 13 0.000051974 2206 X R 1504 / 1536 [xfs_io] 253,0 21 14 0.000055881 2206 X R 1760 / 2016 [xfs_io] 253,0 21 15 0.000057462 2206 X R 1760 / 1792 [xfs_io] 253,0 21 16 0.000060999 2206 X R 2016 / 2272 [xfs_io] 253,0 21 17 0.000062489 2206 X R 2016 / 2048 [xfs_io] 253,0 21 18 0.000066133 2206 X R 2272 / 2528 [xfs_io] 253,0 21 19 0.000067507 2206 X R 2272 / 2304 [xfs_io] 253,0 21 20 0.000071136 2206 X R 2528 / 2784 [xfs_io] 253,0 21 21 0.000072764 2206 X R 2528 / 2560 [xfs_io] 253,0 21 22 0.000076185 2206 X R 2784 / 3040 [xfs_io] 253,0 21 23 0.000077486 2206 X R 2784 / 2816 [xfs_io] 253,0 21 24 0.000080885 2206 X R 3040 / 3296 [xfs_io] 253,0 21 25 0.000082316 2206 X R 3040 / 3072 [xfs_io] 253,0 21 26 0.000085788 2206 X R 3296 / 3552 [xfs_io] 253,0 21 27 0.000087096 2206 X R 3296 / 3328 [xfs_io] 253,0 21 28 0.000093469 2206 X R 3552 / 3808 [xfs_io] 253,0 21 29 0.000095186 2206 X R 3552 / 3584 [xfs_io] 253,0 21 30 0.000099228 2206 X R 3808 / 4064 [xfs_io] 253,0 21 31 0.000101062 2206 X R 3808 / 3840 [xfs_io] 253,0 21 32 0.000104956 2206 X R 4064 / 4096 [xfs_io] 253,0 21 33 0.001138823 0 C R 4096 + 200 [0] after this revert: 253,0 18 1 0.000000000 4430 Q R 224 + 3896 [xfs_io] 253,0 18 2 0.000018359 4430 X R 224 / 256 [xfs_io] 253,0 18 3 0.000028898 4430 X R 256 / 512 [xfs_io] 253,0 18 4 0.000033535 4430 X R 512 / 768 [xfs_io] 253,0 18 5 0.000065684 4430 X R 768 / 1024 [xfs_io] 253,0 18 6 0.000091695 4430 X R 1024 / 1280 [xfs_io] 253,0 18 7 0.000098494 4430 X R 1280 / 1536 [xfs_io] 253,0 18 8 0.000114069 4430 X R 1536 / 1792 [xfs_io] 253,0 18 9 0.000129483 4430 X R 1792 / 2048 [xfs_io] 253,0 18 10 0.000136759 4430 X R 2048 / 2304 [xfs_io] 253,0 18 11 0.000152412 4430 X R 2304 / 2560 [xfs_io] 253,0 18 12 0.000160758 4430 X R 2560 / 2816 [xfs_io] 253,0 18 13 0.000183385 4430 X R 2816 / 3072 [xfs_io] 253,0 18 14 0.000190797 4430 X R 3072 / 3328 [xfs_io] 253,0 18 15 0.000197667 4430 X R 3328 / 3584 [xfs_io] 253,0 18 16 0.000218751 4430 X R 3584 / 3840 [xfs_io] 253,0 18 17 0.000226005 4430 X R 3840 / 4096 [xfs_io] 253,0 18 18 0.000250404 4430 Q R 4120 + 176 [xfs_io] 253,0 18 19 0.000847708 0 C R 4096 + 24 [0] 253,0 18 20 0.000855783 0 C R 4120 + 176 [0] Fixes: effd58c95f27774 ("dm: always call blk_queue_split() in dm_process_bio()") Cc: stable@vger.kernel.org Reported-by: Andreas Gruenbacher Tested-by: Barry Marson Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1739,8 +1739,9 @@ static blk_qc_t dm_process_bio(struct ma * won't be imposed. */ if (current->bio_list) { - blk_queue_split(md->queue, &bio); - if (!is_abnormal_io(bio)) + if (is_abnormal_io(bio)) + blk_queue_split(md->queue, &bio); + else dm_queue_split(md, ti, &bio); }