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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 B187EC48BE5 for ; Mon, 21 Jun 2021 19:55:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8A51260FF1 for ; Mon, 21 Jun 2021 19:55:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231937AbhFUT6E (ORCPT ); Mon, 21 Jun 2021 15:58:04 -0400 Received: from vulcan.natalenko.name ([104.207.131.136]:59528 "EHLO vulcan.natalenko.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231560AbhFUT6D (ORCPT ); Mon, 21 Jun 2021 15:58:03 -0400 Received: from spock.localnet (unknown [151.237.229.131]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by vulcan.natalenko.name (Postfix) with ESMTPSA id E819EAEF2DB; Mon, 21 Jun 2021 21:55:37 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=natalenko.name; s=dkim-20170712; t=1624305338; h=from:from:reply-to:subject:subject: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=rfMnv1hAPpBDenMisM/ic2ybNve50XEt6xLNZNWwwdk=; b=bCWr771Yaf9x68FTv2Eq5A4ecO+TBq4HAfiB48B56v021YKlcJlsF2Xnp3DHNIqiDTvPOA un5QIEjtZpkef85kmJJZL6szd3BR5G1nMREAJSQdSBjxcWhNuKLeq+VpAzRN0WnAwKLjaT FBVqDz+lV9Durkba6xAFVWsDbEngX2c= From: Oleksandr Natalenko To: Jens Axboe , Paolo Valente Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, mariottiluca1@hotmail.it, holger@applied-asynchrony.com, pedroni.pietro.96@gmail.com, Paolo Valente , Piotr Gorski Subject: Re: [PATCH FIXES/IMPROVEMENTS 0/7] block, bfq: preserve control, boost throughput, fix bugs Date: Mon, 21 Jun 2021 21:55:36 +0200 Message-ID: <3533087.dJKXTdksHR@spock> In-Reply-To: <20210619140948.98712-1-paolo.valente@linaro.org> References: <20210619140948.98712-1-paolo.valente@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Hello. On sobota 19. =C4=8Dervna 2021 16:09:41 CEST Paolo Valente wrote: > Hi Jens, > this series contains an already proposed patch by Luca, plus six new > patches. The goals of these patches are summarized in the subject of > this cover letter. I'm including Luca's patch here, because it enabled > the actual use of stable merge, and, as such, triggered an otherwise > silent bug. This series contains also the fix for that bug ("block, > bfq: avoid delayed merge of async queues"), tested by Holger [1]. >=20 > Thanks, > Paolo >=20 > [1] https://lkml.org/lkml/2021/5/18/384 >=20 > Luca Mariotti (1): > block, bfq: fix delayed stable merge check >=20 > Paolo Valente (5): > block, bfq: let also stably merged queues enjoy weight raising > block, bfq: consider also creation time in delayed stable merge > block, bfq: avoid delayed merge of async queues > block, bfq: check waker only for queues with no in-flight I/O > block, bfq: reset waker pointer with shared queues >=20 > Pietro Pedroni (1): > block, bfq: boost throughput by extending queue-merging times >=20 > block/bfq-iosched.c | 68 +++++++++++++++++++++++++++++++++++---------- > 1 file changed, 53 insertions(+), 15 deletions(-) >=20 > -- > 2.20.1 Not sure everything goes fine here. After applying this series on top of th= e=20 latest stable 5.12 kernel I got this: ``` [16730.963248] kernel BUG at block/elevator.c:236! [16730.963254] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [16730.963257] CPU: 11 PID: 109170 Comm: kworker/u64:5 Tainted: G W = =20 5.12.0-pf7 #1 [16730.963260] Hardware name: ASUS System Product Name/Pro WS X570-ACE, BIO= S=20 3601 05/26/2021 [16730.963263] Workqueue: dm-thin do_worker [dm_thin_pool] [16730.963270] RIP: 0010:elv_rqhash_find+0xcc/0xd0 [16730.963274] Code: 41 89 f0 81 e2 00 40 06 00 41 81 e0 1a 00 04 00 44 09 = c2=20 75 a9 be 09 00 00 00 c4 e2 4b f7 50 28 48 03 50 30 48 39 fa 75 c6 c3 <0f> 0= b=20 66 90 0f 1f 44 00 00 41 56 41 55 41 54 55 53 48 8b 47 68 48 [16730.963276] RSP: 0018:ffffa558d13b7af8 EFLAGS: 00010046 [16730.963279] RAX: ffff8a0007782d00 RBX: ffff8a0014b93000 RCX: ffffa558d13= b7b78 [16730.963281] RDX: ffff8a0014b93000 RSI: 0000000000063082 RDI: 000000001e0= fdc00 [16730.963283] RBP: ffff8a000731c770 R08: ffff8a000731c770 R09: fffffff0fff= fddfb [16730.963284] R10: 0000000000000000 R11: 0000000000000400 R12: ffff8a03303= 65c00 [16730.963286] R13: ffffa558d13b7b30 R14: 0000000000000000 R15: ffff8a0212f= c4000 [16730.963288] FS: 0000000000000000(0000) GS:ffff8a070ecc0000(0000) knlGS: 0000000000000000 [16730.963290] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [16730.963292] CR2: 00007f1514d90f4c CR3: 0000000315952000 CR4:=20 0000000000350ee0 [16730.963294] Call Trace: [16730.963297] elv_merge+0x96/0x120 [16730.963300] blk_mq_sched_try_merge+0x3e/0x370 [16730.963303] bfq_bio_merge+0xd3/0x130 [16730.963306] blk_mq_submit_bio+0x11e/0x6c0 [16730.963309] submit_bio_noacct+0x457/0x530 [16730.963312] raid10_unplug+0x13f/0x1a0 [raid10] [16730.963316] blk_flush_plug_list+0xa9/0x110 [16730.963319] blk_finish_plug+0x21/0x30 [16730.963322] process_prepared_discard_passdown_pt1+0x204/0x2d0=20 [dm_thin_pool] [16730.963327] do_worker+0x18e/0xce0 [dm_thin_pool] [16730.963335] process_one_work+0x217/0x3e0 [16730.963338] worker_thread+0x4d/0x470 [16730.963343] kthread+0x182/0x1b0 [16730.963349] ret_from_fork+0x22/0x30 =E2=80=A6 [16730.963419] ---[ end trace dd7e037f2028257b ]--- [16730.963524] RIP: 0010:elv_rqhash_find+0xcc/0xd0 =E2=80=A6 [16730.963547] note: kworker/u64:5[109170] exited with preempt_count 1 [16747.948467] [drm:amdgpu_dm_atomic_commit_tail [amdgpu]] *ERROR* Waiting = for=20 fences timed out! ``` Which is: ``` 229 struct request *elv_rqhash_find(struct request_queue *q, sector_t offse= t) 230 { =E2=80=A6 235 hash_for_each_possible_safe(e->hash, rq, next, hash, offset) { 236 BUG_ON(!ELV_ON_HASH(rq)); =E2=80=A6 ``` Yes, I carry some extra patches besides this series (the list is against v5= =2E12=20 GA): ``` block, bfq: reset waker pointer with shared queues block, bfq: check waker only for queues with no in-flight I/O block, bfq: avoid delayed merge of async queues block, bfq: boost throughput by extending queue-merging times block, bfq: consider also creation time in delayed stable merge block, bfq: fix delayed stable merge check block, bfq: let also stably merged queues enjoy weight raising block: Do not pull requests from the scheduler when we cannot dispatch them blk: Fix lock inversion between ioc lock and bfqd lock bfq: Remove merged request already in bfq_requests_merged() block, bfq: avoid circular stable merges bfq: remove unnecessary BFQ_DEFAULT_GRP_IOPRIO bfq: reset entity->prio_changed in bfq_init_entity() bfq: optimize the calculation of bfq_weight_to_ioprio() bfq: remove unnecessary initialization logic bfq: keep the minimun bandwidth for CLASS_BE bfq: limit the IO depth of CLASS_IDLE to 1 bfq: convert the type of bfq_group.bfqd to bfq_data* bfq: introduce bfq_entity_to_bfqg helper method bfq/mq-deadline: remove redundant check for passthrough request blk-mq: bypass IO scheduler's limit_depth for passthrough request block,bfq: fix the timeout calculation in bfq_bfqq_charge_time block, bfq: merge bursts of newly-created queues block, bfq: keep shared queues out of the waker mechanism block, bfq: fix weight-raising resume with !low_latency block, bfq: make shared queues inherit wakers block, bfq: put reqs of waker and woken in dispatch list block, bfq: always inject I/O of queues blocked by wakers ``` but nothing from there triggered this for quite some time. Paolo, what do you think? =2D-=20 Oleksandr Natalenko (post-factum)