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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95C1CC25B0E for ; Tue, 16 Aug 2022 15:25:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231822AbiHPPZl (ORCPT ); Tue, 16 Aug 2022 11:25:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41086 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235001AbiHPPZ2 (ORCPT ); Tue, 16 Aug 2022 11:25:28 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 83B8D38A0; Tue, 16 Aug 2022 08:25:26 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 153CD1FE6C; Tue, 16 Aug 2022 15:25:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1660663525; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ncy2NIOvh+ZpdU4NuJ/E1ysROFUkTZq4pOGvSv79QFc=; b=spgci90No15kGB3tM9JMpKdAAbKEaCfPNRC4Oy5nXsXzDvNKtwOJv/FxHg27QH91BfI5tY bDg68rLt6QwoocW9BqZEVzqGfS3ZDxPikFEr595KILWHtUWiDiy2Iq0flCUsFRR9Jj8Cwj 5u5k5ij3qFS22ijqEvr674lzUdVlcyI= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 92F5C1345B; Tue, 16 Aug 2022 15:25:24 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id AewjIeS2+2LKHwAAMHmgww (envelope-from ); Tue, 16 Aug 2022 15:25:24 +0000 Message-ID: Date: Tue, 16 Aug 2022 18:25:23 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: stalling IO regression since linux 5.12, through 5.18 Content-Language: en-US To: Chris Murphy , Jens Axboe , Jan Kara , Paolo Valente Cc: Btrfs BTRFS , Linux-RAID , linux-block , linux-kernel , Josef Bacik References: <2220d403-e443-4e60-b7c3-d149e402c13e@www.fastmail.com> <61e5ccda-a527-4fea-9850-91095ffa91c4@www.fastmail.com> <4995baed-c561-421d-ba3e-3a75d6a738a3@www.fastmail.com> From: Nikolay Borisov In-Reply-To: <4995baed-c561-421d-ba3e-3a75d6a738a3@www.fastmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16.08.22 г. 17:22 ч., Chris Murphy wrote: > > > On Sun, Aug 14, 2022, at 4:28 PM, Chris Murphy wrote: >> On Fri, Aug 12, 2022, at 2:02 PM, Jens Axboe wrote: >>> Might be worth trying to revert those from 5.12 to see if they are >>> causing the issue? Jan, Paolo - does this ring any bells? >> >> git log --oneline --no-merges v5.11..c03c21ba6f4e > bisect.txt >> >> I tried checking out a33df75c6328, which is right before the first bfq >> commit, but that kernel won't boot the hardware. >> >> Next I checked out v5.12, then reverted these commits in order (that >> they were found in the bisect.txt file): >> >> 7684fbde4516 bfq: Use only idle IO periods for think time calculations >> 28c6def00919 bfq: Use 'ttime' local variable >> 41e76c85660c bfq: Avoid false bfq queue merging >>>>> a5bf0a92e1b8 bfq: bfq_check_waker() should be static >> 71217df39dc6 block, bfq: make waker-queue detection more robust >> 5a5436b98d5c block, bfq: save also injection state on queue merging >> e673914d52f9 block, bfq: save also weight-raised service on queue merging >> d1f600fa4732 block, bfq: fix switch back from soft-rt weitgh-raising >> 7f1995c27b19 block, bfq: re-evaluate convenience of I/O plugging on rq arrivals >> eb2fd80f9d2c block, bfq: replace mechanism for evaluating I/O intensity >>>>> 1a23e06cdab2 bfq: don't duplicate code for different paths >> 2391d13ed484 block, bfq: do not expire a queue when it is the only busy >> one >> 3c337690d2eb block, bfq: avoid spurious switches to soft_rt of >> interactive queues >> 91b896f65d32 block, bfq: do not raise non-default weights >> ab1fb47e33dc block, bfq: increase time window for waker detection >> d4fc3640ff36 block, bfq: set next_rq to waker_bfqq->next_rq in waker >> injection >> b5f74ecacc31 block, bfq: use half slice_idle as a threshold to check >> short ttime >> >> The two commits prefixed by >>> above were not previously mentioned by >> Jens, but I reverted them anyway because they showed up in the git log >> command. >> >> OK so, within 10 minutes the problem does happen still. This is >> block/bfq-iosched.c resulting from the above reverts, in case anyone >> wants to double check what I did: >> https://drive.google.com/file/d/1ykU7MpmylJuXVobODWiiaLJk-XOiAjSt/view?usp=sharing > > Any suggestions for further testing? I could try go down farther in the bisect.txt list. The problem is if the hardware falls over on an unbootable kernel, I have to bug someone with LOM access. That's a limited resource. > > How about changing the scheduler either mq-deadline or noop, just to see if this is also reproducible with a different scheduler. I guess noop would imply the blk cgroup controller is going to be disabled