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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id AEFD2C282C1 for ; Fri, 28 Feb 2025 16:25:44 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4533D6B0082; Fri, 28 Feb 2025 11:25:44 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 42987280002; Fri, 28 Feb 2025 11:25:44 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2F24B6B0088; Fri, 28 Feb 2025 11:25:44 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 0FC726B0082 for ; Fri, 28 Feb 2025 11:25:44 -0500 (EST) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 6F6AAAEF70 for ; Fri, 28 Feb 2025 16:25:43 +0000 (UTC) X-FDA: 83169879366.02.FD6956F Received: from mail-lf1-f48.google.com (mail-lf1-f48.google.com [209.85.167.48]) by imf15.hostedemail.com (Postfix) with ESMTP id 2D24DA0013 for ; Fri, 28 Feb 2025 16:25:40 +0000 (UTC) Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=TQO1YBcZ; spf=pass (imf15.hostedemail.com: domain of urezki@gmail.com designates 209.85.167.48 as permitted sender) smtp.mailfrom=urezki@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1740759941; h=from:from:sender: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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=VhXr4TnCA5jbl50+NUvjqkpZysAKnfjV2gvofW855yQ=; b=LwHB+2MVpaNzEaHMGUQIkpaE2ewpxGVj3DaQ7jvKFQKmJ3Mh1WoNzfCvePHcU1ApRGWIBU Qmjq3d37JnmmShA9nGffEONQ7wxUi2UXiHXdGAdFCsCOEzsNkvIUnzuQYA4xEYZad9/3JF 1ZuOGt6uH9bI/n65kYC/PVlfjnDfcfQ= ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=TQO1YBcZ; spf=pass (imf15.hostedemail.com: domain of urezki@gmail.com designates 209.85.167.48 as permitted sender) smtp.mailfrom=urezki@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1740759941; a=rsa-sha256; cv=none; b=dotwBsoQvSvscQSHUMxSL8UX5Rv1Ck6T0lz8uiAlf38kGfkqgmYDp+0Qse38PLOg/mdg9R yx4aGJ+Be5VvCAjgWuqM3AyFxer6+XDVTgcu1g6YOeRaXF8AdXoBXSVlWFHrCI/M/iaJoL W1vQc5FI3MRLIM+cotaaBuWI+d3U0WI= Received: by mail-lf1-f48.google.com with SMTP id 2adb3069b0e04-54843052bcdso2052824e87.1 for ; Fri, 28 Feb 2025 08:25:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1740759939; x=1741364739; darn=kvack.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:from:to:cc:subject:date:message-id:reply-to; bh=VhXr4TnCA5jbl50+NUvjqkpZysAKnfjV2gvofW855yQ=; b=TQO1YBcZCd6s29CiDX19bxlZV+nbBOxn7RpdK53X0vMvWY9OSNFyPtwbXe6W4Ydejc m/pGJ8mgcAilWZ/0G4mLeA3t1LGi6qy3u5Hz3IUtbgl8kcn2Pov5v+GCLhIcv4Ac0sbi vVqSWs+/aQu84r0Yx2g8zUIM8+1wCOv46GvBxl3R9P19d1qCudIPYFIHDlh+SL2BVEZn c5Z01nM1o0vMrSmN/3J9WKmIkQD+9CE3ozLTZUwmlbb8/P/hT1qvr82RRRzjcW2uNpXW KbOySa318Zp3EcyBcgUo3bjrOItLPmgcNBcjMlIVg/c3ex5u3yHVll6h284oAoeZA8wO hXhg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740759939; x=1741364739; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=VhXr4TnCA5jbl50+NUvjqkpZysAKnfjV2gvofW855yQ=; b=AJxFcPTQied0wwJO9G+kqO0BH4zvq35+Uk6RxdqjnSD5/6nqOc5qMBLOa15+f0x2l9 Mf9RU1y7iaDfH2NNs5bOk84g/zWZhP6oxz9B7+JMwR4j7lqH5Tn9G/FubtKdHyZGraTA X7uo3bv7+GDEysjE7oXHUKvpUuXXggkBqsIU0atBnu7LZCh+Ljlwg+im/ey64Hu/Gp4b zXyvheLrhidbKXlNNB4PNfIDvJWkPl5hZ0MUGdv1pvAfWZX1RbcyiUpmVlDJJnTzFUXm vc78wZd0y1N5uaOjYmE8sz4Q25vKfCcXwVVpjFMaO5A5aLBa9nMhssIc14S/vrnYdB3F m6MA== X-Forwarded-Encrypted: i=1; AJvYcCXNoDkVUbA/gT/jAa5xr3RP7Ms5gHBIHTMzmmAh4tKhlTmLE19zNxK9J3BqPSwbAMnLo2JEa0HEng==@kvack.org X-Gm-Message-State: AOJu0YyKa0XaM6UUoKshCF39/uf0KpWpmDxFzyN8U7Ia7wXaVN6Rl6fn CpqkPbjyVTPTDcva5GuQcApWYylVRfrj11PFL3gRzO3XhRf980s9 X-Gm-Gg: ASbGncvE6X0vdYvnB0vx2haF/0kegMC6zhAN77L+hpSs8npCX60qRioL3IWa1Q9oqpq 4WnALpHppb5wot9dtGMxvDGCL4SZmZBKSAYS2NB1l81P5oj9lf/gNlmfZrBkM31MBfKZzaQG8Y5 FJnwyyfmD/cWuGWWwll65kTlf4OWmft2gJxjoqUr01QUQUGsXYurCFj1Oa2BH0YBcbbnWjtiITI gDSnPJHkdtIhCXHppIJt/elGjHDwcp3m99Tyc7Asz0JvdeM4oiNiSLcvA/CEhdKbynzDErr8j3K pE3xEFUkAP7/QjLLwgWxkj6hPiNG3sb0qtFfFKYI/XFA+UMM X-Google-Smtp-Source: AGHT+IFna21yxorFsIsk3fBISDfBJed+oeKfLzGr7m+Mk2HE5gJwcZopqbFpuVreIN6DkPqWVUKzKg== X-Received: by 2002:a05:6512:398e:b0:548:91f6:4328 with SMTP id 2adb3069b0e04-5494c11b516mr1850636e87.15.1740759938890; Fri, 28 Feb 2025 08:25:38 -0800 (PST) Received: from pc636 (host-95-203-6-24.mobileonline.telia.com. [95.203.6.24]) by smtp.gmail.com with ESMTPSA id 2adb3069b0e04-549443cb6ccsm546497e87.212.2025.02.28.08.25.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 28 Feb 2025 08:25:38 -0800 (PST) From: Uladzislau Rezki X-Google-Original-From: Uladzislau Rezki Date: Fri, 28 Feb 2025 17:25:35 +0100 To: Vlastimil Babka Cc: "Uladzislau Rezki (Sony)" , linux-mm@kvack.org, Andrew Morton , RCU , LKML , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, Oleksiy Avramchenko , stable@vger.kernel.org, Greg Kroah-Hartman , Keith Busch Subject: Re: [PATCH v1 2/2] mm/slab/kvfree_rcu: Switch to WQ_MEM_RECLAIM wq Message-ID: References: <20250228121356.336871-1-urezki@gmail.com> <20250228121356.336871-2-urezki@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Stat-Signature: u8pjzypg519yscb7pbyszjpj1jm3johf X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 2D24DA0013 X-Rspam-User: X-HE-Tag: 1740759940-144534 X-HE-Meta: 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 2fpiafdS 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Feb 28, 2025 at 03:42:02PM +0100, Vlastimil Babka wrote: > On 2/28/25 13:13, Uladzislau Rezki (Sony) wrote: > > Currently kvfree_rcu() APIs use a system workqueue which is > > "system_unbound_wq" to driver RCU machinery to reclaim a memory. > > > > Recently, it has been noted that the following kernel warning can > > be observed: > > > > > > workqueue: WQ_MEM_RECLAIM nvme-wq:nvme_scan_work is flushing !WQ_MEM_RECLAIM events_unbound:kfree_rcu_work > > WARNING: CPU: 21 PID: 330 at kernel/workqueue.c:3719 check_flush_dependency+0x112/0x120 > > Modules linked in: intel_uncore_frequency(E) intel_uncore_frequency_common(E) skx_edac(E) ... > > CPU: 21 UID: 0 PID: 330 Comm: kworker/u144:6 Tainted: G E 6.13.2-0_g925d379822da #1 > > Hardware name: Wiwynn Twin Lakes MP/Twin Lakes Passive MP, BIOS YMM20 02/01/2023 > > Workqueue: nvme-wq nvme_scan_work > > RIP: 0010:check_flush_dependency+0x112/0x120 > > Code: 05 9a 40 14 02 01 48 81 c6 c0 00 00 00 48 8b 50 18 48 81 c7 c0 00 00 00 48 89 f9 48 ... > > RSP: 0018:ffffc90000df7bd8 EFLAGS: 00010082 > > RAX: 000000000000006a RBX: ffffffff81622390 RCX: 0000000000000027 > > RDX: 00000000fffeffff RSI: 000000000057ffa8 RDI: ffff88907f960c88 > > RBP: 0000000000000000 R08: ffffffff83068e50 R09: 000000000002fffd > > R10: 0000000000000004 R11: 0000000000000000 R12: ffff8881001a4400 > > R13: 0000000000000000 R14: ffff88907f420fb8 R15: 0000000000000000 > > FS: 0000000000000000(0000) GS:ffff88907f940000(0000) knlGS:0000000000000000 > > CR2: 00007f60c3001000 CR3: 000000107d010005 CR4: 00000000007726f0 > > PKRU: 55555554 > > Call Trace: > > > > ? __warn+0xa4/0x140 > > ? check_flush_dependency+0x112/0x120 > > ? report_bug+0xe1/0x140 > > ? check_flush_dependency+0x112/0x120 > > ? handle_bug+0x5e/0x90 > > ? exc_invalid_op+0x16/0x40 > > ? asm_exc_invalid_op+0x16/0x20 > > ? timer_recalc_next_expiry+0x190/0x190 > > ? check_flush_dependency+0x112/0x120 > > ? check_flush_dependency+0x112/0x120 > > __flush_work.llvm.1643880146586177030+0x174/0x2c0 > > flush_rcu_work+0x28/0x30 > > kvfree_rcu_barrier+0x12f/0x160 > > kmem_cache_destroy+0x18/0x120 > > bioset_exit+0x10c/0x150 > > disk_release.llvm.6740012984264378178+0x61/0xd0 > > device_release+0x4f/0x90 > > kobject_put+0x95/0x180 > > nvme_put_ns+0x23/0xc0 > > nvme_remove_invalid_namespaces+0xb3/0xd0 > > nvme_scan_work+0x342/0x490 > > process_scheduled_works+0x1a2/0x370 > > worker_thread+0x2ff/0x390 > > ? pwq_release_workfn+0x1e0/0x1e0 > > kthread+0xb1/0xe0 > > ? __kthread_parkme+0x70/0x70 > > ret_from_fork+0x30/0x40 > > ? __kthread_parkme+0x70/0x70 > > ret_from_fork_asm+0x11/0x20 > > > > ---[ end trace 0000000000000000 ]--- > > > > > > To address this switch to use of independent WQ_MEM_RECLAIM > > workqueue, so the rules are not violated from workqueue framework > > point of view. > > > > Apart of that, since kvfree_rcu() does reclaim memory it is worth > > to go with WQ_MEM_RECLAIM type of wq because it is designed for > > this purpose. > > > > Cc: > > Cc: Greg Kroah-Hartman > > stable is sufficient, no need for greg himself too > > > Cc: Keith Busch > > Closes: https://www.spinics.net/lists/kernel/msg5563270.html > > lore pls :) > Thanks, got it. I tried but did not find the link :) > > Fixes: 6c6c47b063b5 ("mm, slab: call kvfree_rcu_barrier() from kmem_cache_destroy()"), > > Reported-by: Keith Busch > > Signed-off-by: Uladzislau Rezki (Sony) > > fixed locally and pushed to slab/for-next-fixes > thanks! > Thanks! -- Uladzislau Rezki