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 C72EFC433EF for ; Wed, 18 May 2022 22:29:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229809AbiERW3l (ORCPT ); Wed, 18 May 2022 18:29:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39086 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229760AbiERW3k (ORCPT ); Wed, 18 May 2022 18:29:40 -0400 Received: from mail-pl1-x62a.google.com (mail-pl1-x62a.google.com [IPv6:2607:f8b0:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D7C5721A94F for ; Wed, 18 May 2022 15:29:37 -0700 (PDT) Received: by mail-pl1-x62a.google.com with SMTP id d22so3097462plr.9 for ; Wed, 18 May 2022 15:29:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=GHsUE9N7qwGKPhSfb7FLSZbI7huX80ouMGDrIjhw1Uk=; b=tok1tK7PAPs2jl/A5+MZDuzJGG74i7qajPVXyIwM3P53jmWgJKGEW7xAVxKnCBpMuW BnKA1MeavVlAHM+qmVYN405lR1GJKzR3fFBXM+n9IgkNThCrONTNOshTDllOgV0aSm2S bpSoI4pRydA/Nn0a0wlg8oLEhiZYRUn3g4325mDVoqBkb0dNlvbTWfaHzn7ZNlNUotWk lNm6knKRwz6jFbdE+onYhm26Cb5FxhurSbjVKHHpKViUX4kmpXEpRm4R4Hv64WsaZg+D s5CpNv4rgXS9RqIgdp3zMSXg1UwgClwDlEWUmWfSEUD++9eq0DBNYmbksnJwUu9qNd6E qINQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=GHsUE9N7qwGKPhSfb7FLSZbI7huX80ouMGDrIjhw1Uk=; b=bgqZPbyQ9mGDLJ4txlVQJDRfnUzqmSAjX21WMXxY7Nxs+XYwBDXCgHbM2xHZtGC8i8 6CDlGRgnG7OKkupQvsm9MBBnDpoyDhVal6MlLG7HRGHTZ6/N10lf3M6JlnH4/9RodcVs obNHz6Gq40ckFt/a3rJxDXYRW8xu8t3yOg12HieIglcFWlPeRMOGT+p8e8EtfOKpfHrt MsglZ/vmfd6KYfM/bG21A5dN/Vz3TC8OOGYUJ+XFx8scILiq354K5d1Ngyzrq/de58fC A3LjdWJGrFgtyxfdih6WnPKpIQtgh2e9samrD/s9zE7RCRpx4+/fyQ9cq38U95P31uxK GiRg== X-Gm-Message-State: AOAM532ch8WxoN94YezhlPGEM99H5l/4DmfgDmiK+Vwysa2ITVdJLaOD D8F3BGMgsgpTUK0UCsQdgT0P7jRkBF1GSw== X-Google-Smtp-Source: ABdhPJxPQ+3/S+p5wkyoI6EnBIr0Se7SP74lvulMafErZTqa/eRb6oco6NUfBqYfRV0hsIvy7arjyA== X-Received: by 2002:a17:90a:3e81:b0:1df:4c26:1786 with SMTP id k1-20020a17090a3e8100b001df4c261786mr1707941pjc.126.1652912977258; Wed, 18 May 2022 15:29:37 -0700 (PDT) Received: from [192.168.1.100] ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id im15-20020a170902bb0f00b001616723b8ddsm2231887plb.45.2022.05.18.15.29.35 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 18 May 2022 15:29:36 -0700 (PDT) Message-ID: <1dad86bb-ae31-5bf8-5810-9e81c68be8ff@kernel.dk> Date: Wed, 18 May 2022 16:29:35 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:91.0) Gecko/20100101 Thunderbird/91.8.1 Subject: Re: [PATCH] blk-cgroup: Remove unnecessary rcu_read_lock/unlock() Content-Language: en-US To: Marek Szyprowski , bh1scw@gmail.com, tj@kernel.org Cc: cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, songmuchun@bytedance.com References: <20220516173930.159535-1-bh1scw@gmail.com> <46253c48-81cb-0787-20ad-9133afdd9e21@samsung.com> From: Jens Axboe In-Reply-To: <46253c48-81cb-0787-20ad-9133afdd9e21@samsung.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 5/18/22 1:28 PM, Marek Szyprowski wrote: > On 16.05.2022 19:39, bh1scw@gmail.com wrote: >> From: Fanjun Kong >> >> spin_lock_irq/spin_unlock_irq contains preempt_disable/enable(). >> Which can serve as RCU read-side critical region, so remove >> rcu_read_lock/unlock(). >> >> Signed-off-by: Fanjun Kong > > This patch landed in today's linux next-20220518 as commit 77c570a1ea85 > ("blk-cgroup: Remove unnecessary rcu_read_lock/unlock()"). > > Unfortunately it triggers the following warning on ARM64 based Raspberry > Pi 4B board:> > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 1 at block/blk-cgroup.c:301 blkg_create+0x398/0x4e0 Should this use rcu_read_lock_any_held() rather than rcu_read_lock_held()? -- Jens Axboe