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=-3.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FSL_HELO_FAKE, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 B27D6C07E95 for ; Tue, 13 Jul 2021 13:19:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 995D761166 for ; Tue, 13 Jul 2021 13:19:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236329AbhGMNWr (ORCPT ); Tue, 13 Jul 2021 09:22:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56770 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236283AbhGMNWr (ORCPT ); Tue, 13 Jul 2021 09:22:47 -0400 Received: from mail-pf1-x435.google.com (mail-pf1-x435.google.com [IPv6:2607:f8b0:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AB00BC0613DD for ; Tue, 13 Jul 2021 06:19:57 -0700 (PDT) Received: by mail-pf1-x435.google.com with SMTP id 21so19593409pfp.3 for ; Tue, 13 Jul 2021 06:19:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:mime-version:content-disposition; bh=sYaLI5hREs6S0GCn5kt31M6b+bWhHLGZQ73MTTA23MY=; b=E60K6rOVubJWxCl5FlN6nDmOD5MG0l6g8MRW71VqK/ZgOuHK4IIFJUJs2rkCsCqq5X JTXOWjW9k0MiBAVxgm3NhAXgVJGVqELXGp+RLSOkUORU3bwV7d3UV4YyvjLYYUTfQtKX wR6a2Ksg+z+gj5loBep8jhT2BEjD7HR82E//8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition; bh=sYaLI5hREs6S0GCn5kt31M6b+bWhHLGZQ73MTTA23MY=; b=ODdqSA3T6WD/63Lrr5wrpA5LjFxZW2E+uDm3XdUH3ZDvRtMCYvQf2G43MDFFVpvTRV W3QfNsrpY70TE4saCgZNnpPWwaGk2vcQXtzqffLMpWvPNNZxZ9UxwfeLEu0iZZ/k3IVo pE3EwL73LDOApWdwWYjcgOEDoe/Oprb5c4K8+FiJA7Zphk9a2FgWzf+kmcVLifgWMSuK WxwX6Tfc4m0h6Lm9DYq1ADefTRpP6SxrB+EJ077QdwhUj5YoJBx9fvtZRFeAsKPG3F7N UU1Gyj9ephseDH2ZnNwbCi28xcrf/bqoe2y1xvd9rfJMO8BGXRtPhFOCLUtAOoilkkdb 0Cng== X-Gm-Message-State: AOAM5302o4dFkZeDNx4VKmWN+JQss0VBskNN6LosaIvlgN6Q3ggcEZgT wWR1u3TRcxkVxOU+xTUNk4tw3A== X-Google-Smtp-Source: ABdhPJz/Hrby3BnB86LdkmOz8m+7CJUogDKjNLjMHs2y7/3yHj8hq2Nfoie3OSv1kUQRR8RBUGrQ9Q== X-Received: by 2002:aa7:82cb:0:b029:2e6:f397:d248 with SMTP id f11-20020aa782cb0000b02902e6f397d248mr4759999pfn.52.1626182397180; Tue, 13 Jul 2021 06:19:57 -0700 (PDT) Received: from google.com ([2409:10:2e40:5100:e304:7803:b108:f108]) by smtp.gmail.com with ESMTPSA id d129sm19492414pfd.218.2021.07.13.06.19.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Jul 2021 06:19:56 -0700 (PDT) Date: Tue, 13 Jul 2021 22:19:52 +0900 From: Sergey Senozhatsky To: Sebastian Andrzej Siewior , John Johansen Cc: Peter Zijlstra , Tomasz Figa , linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org Subject: apparmor: global buffers spin lock may get contended Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Precedence: bulk List-ID: Hi, We've notices that apparmor has switched from using per-CPU buffer pool and per-CPU spin_lock to a global spin_lock in df323337e507a0009d3db1ea. This seems to be causing some contention on our build machines (with quite a bit of cores). Because that global spin lock is a part of the stat() sys call (and perhaps some other) E.g. - 9.29% 0.00% clang++ [kernel.vmlinux] - 9.28% entry_SYSCALL_64_after_hwframe - 8.98% do_syscall_64 - 7.43% __do_sys_newlstat - 7.43% vfs_statx - 7.18% security_inode_getattr - 7.15% apparmor_inode_getattr - aa_path_perm - 3.53% aa_get_buffer - 3.47% _raw_spin_lock 3.44% native_queued_spin_lock_slowpath - 3.49% aa_put_buffer.part.0 - 3.45% _raw_spin_lock 3.43% native_queued_spin_lock_slowpath Can we fix this contention?