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=-7.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 EFE81C433DF for ; Sat, 18 Jul 2020 08:34:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CD4D72073E for ; Sat, 18 Jul 2020 08:34:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="iU4puuJ1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729000AbgGRIet (ORCPT ); Sat, 18 Jul 2020 04:34:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41374 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728749AbgGRIet (ORCPT ); Sat, 18 Jul 2020 04:34:49 -0400 Received: from mail-lj1-x242.google.com (mail-lj1-x242.google.com [IPv6:2a00:1450:4864:20::242]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E228BC0619D2; Sat, 18 Jul 2020 01:34:48 -0700 (PDT) Received: by mail-lj1-x242.google.com with SMTP id h22so15263180lji.9; Sat, 18 Jul 2020 01:34:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=8LxBXucu22MekJzjcm9McVLQ6xx8d1C2UxhUn5AUQVA=; b=iU4puuJ1t9aQMFxcrQUpwAs55vm9CVnCD+SxkQcdPDYW5ntHPRX0LUfd0sKfC71g1g DckdRLgA9DgEKRohMh5hy2PUfgl5+HH/dcJqJRIXgPYa5agDwpAwdA6xJSKtQIccyaXJ vshX+FmSy0o70KEY8Fvh2j9p5t4yECPswn4rh1g+vEPTX4VnoAgLl5O9uGcxoq2HgbV4 Vrxfh0mKMUGq86Hglo5ypwPKHrJBHmrzzSKPMS7HGACzXjbHGtn20ykZfhVsgZHgZUhQ iEXhlWxHfXj3lMfnI/dKxPlb95aqYYv1qu2SYILEfMffZoH6ziqjSt7938R8szpinQhr 3qMg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=8LxBXucu22MekJzjcm9McVLQ6xx8d1C2UxhUn5AUQVA=; b=sDSwhFH3HAV1ZHRaQwbKqe/9Myt0gfYKgaBLyes5Lj74Qd1mzh3J5bAgazzJrvQiZ+ /eoLWU46bo+yRKLjJYOxdbiGmhfow2PeowX0iQsd2Sidq2zMLxKB6gAR6rm2G6c+1iRw Iz4kofBtoYjhbRaOeCK3lh8FQtHy3JSlN+T7j+nOT5nBzm8ICxC1PwXywkMRQJDwRIKS Jiqw3NNIDu/7ZG2IUy/uA0H9y8SsDkfT7+FU9VZYh2P/yFMJmVH2dJPbrZAf+8qF9i8D PdHFSJBKc+toyEuAH4EJ9OJ63wsmSYhiyM1FHAaEpH1oTZwm3p7oSB268Dy3Rg0Q2sjY nvew== X-Gm-Message-State: AOAM5321n+W2BSvUtBgMm0pJWF0GwfcUPN5tSGwj+DKFweqiDT4UKfVk m9lgAiQbYv1ZZOBGV2YFsl/MO3xN X-Google-Smtp-Source: ABdhPJwfdy/KeGasBEr5jNeY291r6rmQZNvkJfzhUpsbYSckT2da/NemRlp8JGmePxIYJmPxAtS5AA== X-Received: by 2002:a2e:93d5:: with SMTP id p21mr5560378ljh.239.1595061287383; Sat, 18 Jul 2020 01:34:47 -0700 (PDT) Received: from localhost.localdomain ([82.209.196.123]) by smtp.gmail.com with ESMTPSA id u26sm2789226lfq.72.2020.07.18.01.34.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 18 Jul 2020 01:34:46 -0700 (PDT) From: Pavel Begunkov To: Jens Axboe , io-uring@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 0/2] task_put batching Date: Sat, 18 Jul 2020 11:32:50 +0300 Message-Id: X-Mailer: git-send-email 2.24.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For my a bit exaggerated test case perf continues to show high CPU cosumption by io_dismantle(), and so calling it io_iopoll_complete(). Even though the patch doesn't yield throughput increase for my setup, probably because the effect is hidden behind polling, but it definitely improves relative percentage. And the difference should only grow with increasing number of CPUs. Another reason to have this is that atomics may affect other parallel tasks (e.g. which doesn't use io_uring) before: io_iopoll_complete: 5.29% io_dismantle_req: 2.16% after: io_iopoll_complete: 3.39% io_dismantle_req: 0.465% Pavel Begunkov (2): tasks: add put_task_struct_many() io_uring: batch put_task_struct() fs/io_uring.c | 28 ++++++++++++++++++++++++++-- include/linux/sched/task.h | 6 ++++++ 2 files changed, 32 insertions(+), 2 deletions(-) -- 2.24.0