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 2CA8AE95A61 for ; Sat, 7 Oct 2023 15:50:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344053AbjJGPum (ORCPT ); Sat, 7 Oct 2023 11:50:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49146 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344038AbjJGPul (ORCPT ); Sat, 7 Oct 2023 11:50:41 -0400 Received: from mail-oi1-x22a.google.com (mail-oi1-x22a.google.com [IPv6:2607:f8b0:4864:20::22a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D4EF9BF; Sat, 7 Oct 2023 08:50:40 -0700 (PDT) Received: by mail-oi1-x22a.google.com with SMTP id 5614622812f47-3af604c3f8fso2098734b6e.1; Sat, 07 Oct 2023 08:50:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1696693840; x=1697298640; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=bRb4xyVggbiNdF/CuWm/83mjhA2PGKIdFUSg0RWfnOE=; b=NVc0hYUUBqTebhXu5sTTZTz9hNNpT7vy+t73CmmHG1D/fIBDRsQGl7zMjQ0XfnLff8 Y/vWbrZaiecPfW24b1R3e8cbmv0r0pvkp/8eZu7Gt5sbBw1c+Y59elP0zpb7qp3wyXIz dqKnUwOGYBpmQlLJevqNHjTd2cIF39v7FpURQJLeWA5tb2RwkDG+IwSdkqwHE2zmFjFX iehEWtviuK3UPD1vx8WvanKYCkzEoQH/tzSxb15gzeduQlyYIab/OVz1QJN4Igg9WV6H 3t9mBL1Vz4Niuh9761lm4wmaLgvw1Ka5WKVzYGn8nmPVsZ2+k9nnB9tQcxvdmVPYGYKC 5Deg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696693840; x=1697298640; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=bRb4xyVggbiNdF/CuWm/83mjhA2PGKIdFUSg0RWfnOE=; b=dsTn788J/CoHMCk5p7SDXxemyk+n7+l5NQ4MqaDDjwcxL/Bxd0sT/c31Lv5h0SxTut L7MjBos9N3QtxKAbz5f0mhVqKen3mYjtQ9wAWfnga+Pjmsw/+0tE757MNLQO4BR9LIUd PwYFyRYWrVjSHQCGNK7/2ttPkC4XgPHPfCYKVXwcuH1QH1wXeVRc1dhqbQ6ioIhFP/T7 kRzbY2KZx0iw2qv2pw6RATJJC79l7hR1oCe3WFvVxVFEQpWUdq87cEm1rgFNftZTjXfo 07FqFlTQQ4YJ7ICi3UilbQZqj3sFVORSZ6p5JAue07PFbXaHTtZIvevMQbnrdG1xtug6 cE6A== X-Gm-Message-State: AOJu0YzUASP+ae1A6sXz7UtNMYZmN1uXWPD6DtT6Pv520igWNwPuli72 6Vd8nbEQvxJU91C744TQJfE= X-Google-Smtp-Source: AGHT+IGKDslXMsVHZ8g50T+5zfWAxU0NHbnVre1UM1pKyhAb/W4tJK9zhKPyMcfFooUpuTTGNyvT6A== X-Received: by 2002:a05:6358:988d:b0:143:723:8f89 with SMTP id q13-20020a056358988d00b0014307238f89mr13481795rwa.4.1696693840007; Sat, 07 Oct 2023 08:50:40 -0700 (PDT) Received: from localhost ([2620:10d:c090:400::4:cced]) by smtp.gmail.com with ESMTPSA id d6-20020a17090ad3c600b00256799877ffsm5313614pjw.47.2023.10.07.08.50.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 07 Oct 2023 08:50:39 -0700 (PDT) Sender: Tejun Heo Date: Sat, 7 Oct 2023 05:50:37 -1000 From: Tejun Heo To: Yafang Shao Cc: ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yonghong.song@linux.dev, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, lizefan.x@bytedance.com, hannes@cmpxchg.org, yosryahmed@google.com, mkoutny@suse.com, sinquersw@gmail.com, cgroups@vger.kernel.org, bpf@vger.kernel.org Subject: Re: [RFC PATCH bpf-next 1/8] cgroup: Don't have to hold cgroup_mutex in task_cgroup_from_root() Message-ID: References: <20231007140304.4390-1-laoar.shao@gmail.com> <20231007140304.4390-2-laoar.shao@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231007140304.4390-2-laoar.shao@gmail.com> Precedence: bulk List-ID: X-Mailing-List: cgroups@vger.kernel.org On Sat, Oct 07, 2023 at 02:02:57PM +0000, Yafang Shao wrote: > The task cannot modify cgroups if we have already acquired the > css_set_lock, thus eliminating the need to hold the cgroup_mutex. Following > this change, task_cgroup_from_root() can be employed in non-sleepable contexts. > > Signed-off-by: Yafang Shao Maybe just drop lockdep_assert_held(&cgroup_mutex) from cset_cgroup_from_root()? Thanks. -- tejun