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 ACFFFC021B7 for ; Fri, 21 Feb 2025 16:52:54 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4745828001A; Fri, 21 Feb 2025 11:52:54 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 423B1280016; Fri, 21 Feb 2025 11:52:54 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2EBDD28001A; Fri, 21 Feb 2025 11:52:54 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 0B68B280016 for ; Fri, 21 Feb 2025 11:52:54 -0500 (EST) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id A4534818B5 for ; Fri, 21 Feb 2025 16:52:53 +0000 (UTC) X-FDA: 83144546226.14.8B88ACB Received: from mail-ej1-f44.google.com (mail-ej1-f44.google.com [209.85.218.44]) by imf16.hostedemail.com (Postfix) with ESMTP id B923B180014 for ; Fri, 21 Feb 2025 16:52:51 +0000 (UTC) Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=Pbw2xrpc; spf=pass (imf16.hostedemail.com: domain of mjguzik@gmail.com designates 209.85.218.44 as permitted sender) smtp.mailfrom=mjguzik@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=1740156771; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=vO8sI//TeIWtExyYtaD4Exo5QVqQp3kkPzLWvb0G4ZQ=; b=p+pdHbVrG0YPLfx2h3M2i8HWJ5wNNebkqVDllDy8c/zlKGdYWbOhhVdj1mBAVCZd5m/08k vH4UpGR9b0/Er8ocoVC4wRzktdXMGOObGioeE+gK4ltlVyEpWxj/0iOb0fA7WHGFrmUajU I537Fsna1cIrPUdSQW9Q/p9tY4t1Dwc= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1740156771; a=rsa-sha256; cv=none; b=QjbmPt3VESIJm2/3lnfDLUZmdnEcHIU89U8ApdYvfejSNtQj5fkCB+DS1FtXljf+qs6FfB ZrsCJkS/jDQVxUehjBk0QMpXXvMX4LegKORfLqJaWJ61mnbAahQB+E+bre/Aakj+2YfIJC twoFnK+CAxCaFbANETfIyDkIMy+OlnU= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=Pbw2xrpc; spf=pass (imf16.hostedemail.com: domain of mjguzik@gmail.com designates 209.85.218.44 as permitted sender) smtp.mailfrom=mjguzik@gmail.com; dmarc=pass (policy=none) header.from=gmail.com Received: by mail-ej1-f44.google.com with SMTP id a640c23a62f3a-abb75200275so371723366b.3 for ; Fri, 21 Feb 2025 08:52:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1740156770; x=1740761570; darn=kvack.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=vO8sI//TeIWtExyYtaD4Exo5QVqQp3kkPzLWvb0G4ZQ=; b=Pbw2xrpcnFXKVaBTeOOgLcl5qp6WBb2H4jcWuL0E4T5YY9+3EXB+md+PmlrJMYfUmU VSABBBI/qlKaOuvtGtPkwV6tdE7xgjtkAwB84Qlq4SfbCIUgQx5FoCrHelfB29KhbgWC rbfd4MciUls20xGjK6R/SBIeIy8p1qxV+M1cFQDJyT1kxZ25WO326JClBzffZNQqWhrh 1hfcQlVz9b0ykdCIBMgLubAuOxnGqPSa5suaytIKJYgEaMxQFg09ICjRzHx6TLxB7ebp Qwig4CbNhBtsAkJ3koAApHN0BqAEqw1vixdKGpCctZdNEYiWrRy8fnKXaCzyqFh6FrZV Dutw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740156770; x=1740761570; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=vO8sI//TeIWtExyYtaD4Exo5QVqQp3kkPzLWvb0G4ZQ=; b=SuZQQLbX6JQdMdHa6EBoP/wgnLg+Lbx2iSVenUykGyznhcWNqTZBR1KlTndPHMELhA 9l/aLoYefhOF/Cr8btMUvzFuxt/97GrZC6J8jP4ioa98G5fCmWoOlvTW3Nzdy5uzQJxR N2t5zwKhUBItirU+xUpPTb4Cj7rHZk6wlj+BAoqBTRMy0/MOhMf7xDXE3UVPozP3Mqvt CuwmDmdmzkf8oDGrf45ZXH5WmC3Hsv3khRXRc6/ZsDzjUeCWyUSY9nL3/MOA0PbTiCu4 P3z8wDWwuu1pY40SW104JLF8yPh/7DlKROA6HcEM0XMFKacwi9HmY4gkqlSqrLuA5PTV xAVg== X-Forwarded-Encrypted: i=1; AJvYcCXt4JJfUVhg16dsND0IyUSUqr35kbVxUN2g/eMaVS7kLlEZJ1we5n5tB6w8kHn8I7FVWx6lZ2Nrew==@kvack.org X-Gm-Message-State: AOJu0YxMnP4YQYbIq8tH9uBbualVO9BzNbMSG5JqZDUfLW4nYttQA0vt g2+MU6UhbK+9i8UEPtcEZjeNkGtFR0N9EK0Op/AhYsM4iXqfbighXGHtyTM3kUwO3S8IvfBBeYs e8D+nsWjpbXOxnzVEH4DgkrYncTU= X-Gm-Gg: ASbGnctgngDbtgNeKnozQ+k1fBQX2BPFIsusoxJ2LK28chmbW3lgtwwG8dflVu6fMvK xYQBj6qfdy3Apy2SJKRNvuD8MldNRHIoT1wNoFaVDdPNYcdO0BlOtQ4yhffjvJdD1DE/GMiwT6g VbNuG0Cw== X-Google-Smtp-Source: AGHT+IHpa7dVTFfLnzKGtw2UdVJJ5Ox7pwmBS6uaFDBASq3wQSqM7Dh70sJDq3JmlljMQpfKXkg8quBGs3JbrAY90XA= X-Received: by 2002:a17:907:944b:b0:abb:c647:a4c1 with SMTP id a640c23a62f3a-abc09e37de2mr406314466b.52.1740156770066; Fri, 21 Feb 2025 08:52:50 -0800 (PST) MIME-Version: 1.0 References: <20240807-b4-slab-kfree_rcu-destroy-v2-0-ea79102f428c@suse.cz> <20240807-b4-slab-kfree_rcu-destroy-v2-6-ea79102f428c@suse.cz> In-Reply-To: From: Mateusz Guzik Date: Fri, 21 Feb 2025 17:52:38 +0100 X-Gm-Features: AWEUYZldjsBOz6dW6Mngy0JPyOmqYkSKLBXfGnQS2tXN2Unv8ZD0Hi38e_Hg0os Message-ID: Subject: Re: [PATCH v2 6/7] mm, slab: call kvfree_rcu_barrier() from kmem_cache_destroy() To: Keith Busch Cc: Vlastimil Babka , "Paul E. McKenney" , Joel Fernandes , Josh Triplett , Boqun Feng , Christoph Lameter , David Rientjes , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , Zqiang , Julia Lawall , Jakub Kicinski , "Jason A. Donenfeld" , "Uladzislau Rezki (Sony)" , Andrew Morton , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, linux-mm@kvack.org, linux-kernel@vger.kernel.org, rcu@vger.kernel.org, Alexander Potapenko , Marco Elver , Dmitry Vyukov , kasan-dev@googlegroups.com, Jann Horn , linux-nvme@lists.infradead.org, leitao@debian.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspam-User: X-Rspamd-Queue-Id: B923B180014 X-Rspamd-Server: rspam07 X-Stat-Signature: zid7h7tqfjw7qj1965njbed1fh34x49z X-HE-Tag: 1740156771-189292 X-HE-Meta: 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 VIUi2J9J MHw2y3r66PBqJFjqKKB/vxUI4d7CBQsNsXryZuOpJK/2Sl1O7T2vpYF4dZJuhx8zKmgnPF3/Eo8MIFwxE4mW2MMqzSW1fWUo9zFs2+huXpqDMFnbjRfv+vwLbd9lZyuGZWB3JugxKbNLSs8P1Bag1qwtGq/nE/bamMszEssKMFMTI5kF/VnrVOeqWqf821LoDzkCDhFIJU/cQNLDakCbuhpUxT1CdEEV1KmvUiYMFt6z3Uryf1NzZB/1EyPuOivAF/dr48oMJuaWV+U5/8bDs/glcZ4jPMQeysxE5rq/akCfa53VVbWKrBIoHzQbNLY4ednt9ImU+hFp2qOUhQOpA9+ZbYNmiUXZFbqFvKKzYvyQr+k9m3UJsfcJ6/+TXzFsVh9obbFrJOTGNF7edJmFGAhlKXcDxKYM2XiHSrs71zxUpeX4uJVsMDhff5DXPkU3AmwzmNC+TnseB4sSRpNKNLuvYe/yx1BIVPZ/dZ2j41YdY398= 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 21, 2025 at 5:51=E2=80=AFPM Mateusz Guzik w= rote: > > On Fri, Feb 21, 2025 at 5:30=E2=80=AFPM Keith Busch w= rote: > > This patch appears to be triggering a new warning in certain conditions > > when tearing down an nvme namespace's block device. Stack trace is at > > the end. > > > > The warning indicates that this shouldn't be called from a > > WQ_MEM_RECLAIM workqueue. This workqueue is responsible for bringing up > > and tearing down block devices, so this is a memory reclaim use AIUI. > > I'm a bit confused why we can't tear down a disk from within a memory > > reclaim workqueue. Is the recommended solution to simply remove the WQ > > flag when creating the workqueue? > > > > This ends up calling into bioset_exit -> bio_put_slab -> kmem_cache_destr= oy > > Sizes of the bio- slabs are off the beaten path, so it may be they > make sense to exist. > > With the assumption that caches should be there, this can instead > invoke kmem_cache_destroy from a queue where it is safe to do it. This > is not supposed to be a frequent operation. Erm, I mean defer the operation to a queue which can safely do it. --=20 Mateusz Guzik