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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 D2178C433DB for ; Mon, 11 Jan 2021 03:56:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9467022472 for ; Mon, 11 Jan 2021 03:56:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727170AbhAKD4k (ORCPT ); Sun, 10 Jan 2021 22:56:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43238 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726391AbhAKD4j (ORCPT ); Sun, 10 Jan 2021 22:56:39 -0500 Received: from mail-pl1-x632.google.com (mail-pl1-x632.google.com [IPv6:2607:f8b0:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2B555C061786 for ; Sun, 10 Jan 2021 19:55:59 -0800 (PST) Received: by mail-pl1-x632.google.com with SMTP id t6so8825118plq.1 for ; Sun, 10 Jan 2021 19:55:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=TPpO7uwACT3qF76CIRKljdkA+kPcxYirzS1ReRG4ryw=; b=D7iHpQeGTDnVoH9/flTLwTFSYaUm54qf7IynZXyHFYm720oL5f+7+tRKw0bOd5ce3f 9mT/lB9YGVKtFHhginEetjesTh/GKxEIr8C9xswUxLb9ioPmFPCo1cNEFgvR7JStEy/V sgrH9gmOYhIeWuPBNHcUGche0qKNI5OcIzmw/EKj+MpCZDoUef1njI6jxlkHFwL2XDab za6ybei3hJjcCmbI8ASFrpQocT7XjVKML35rQgxgJE/C/5orYnlEW7qliqYx1fRbo8NG tDjBmKDVzUsau0SKYdruz5iCn9USoGJDkb0VsGwgnVrsbYTInc3gDdRqasXpRrRY8+jt tgxQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=TPpO7uwACT3qF76CIRKljdkA+kPcxYirzS1ReRG4ryw=; b=S967zg5612nWUrjf713pOSRzJw85f0TtZRDfpCR0h0gZgcrBZGadfb+2b9T+MRtLM5 OlJPvrrwbGrca897D7h8rZ728wACBs5oErZsiJ9gOcu28+ncdGglIIYmq+gP46fOwyzR 5mWY3xspf6t6zOvTeaxnshmpNcgKtQRurGylf/veGbeklHKdPG8D2YslzsfE2jhk0Xfb VLkbgmajWmGmej7v10A5AIy/Y0e8AfaZNcQXLaYPnwhPwr2iP9LLOv0dwUxe1SLCkP1w nP37s0KP0hwouWeTBx/9yML7nwqpDawUx0Fwq8A0QCWdqnceiQZ48DkOjlu/KDABx+zj ggoQ== X-Gm-Message-State: AOAM532WdAvuWwWDyk/AkWGH5oKvkoWPvaPh9vwAO7b9NnUZb8cnZBht m1FWf15ixFChMh3U2tZs7iqD8VDCLgKaIg== X-Google-Smtp-Source: ABdhPJwl35ZrGzmHXShiHiqPQiBkrSw7ny6eJKPY4CSl86weSLiskU4c5Wq630Qbbp6ZFqn8qyiYcA== X-Received: by 2002:a17:90a:f683:: with SMTP id cl3mr15990966pjb.136.1610337358822; Sun, 10 Jan 2021 19:55:58 -0800 (PST) Received: from localhost.localdomain ([103.7.29.9]) by smtp.gmail.com with ESMTPSA id o32sm19187816pgm.10.2021.01.10.19.55.57 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sun, 10 Jan 2021 19:55:58 -0800 (PST) From: Jiang Biao X-Google-Original-From: Jiang Biao To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Jiang Biao , Bin Lai Subject: [PATCH] mm/vmstat.c: erase latency in vmstat_shepherd Date: Mon, 11 Jan 2021 11:55:26 +0800 Message-Id: <20210111035526.1511-1-benbjiang@tencent.com> X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jiang Biao Many 100us+ latencies have been deteceted in vmstat_shepherd() on CPX platform which has 208 logic cpus. And vmstat_shepherd is queued every second, which could make the case worse. Add schedule point in vmstat_shepherd() to erase the latency. Signed-off-by: Jiang Biao Reported-by: Bin Lai --- mm/vmstat.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/vmstat.c b/mm/vmstat.c index f8942160fc95..b538199883b5 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -1953,6 +1953,8 @@ static void vmstat_shepherd(struct work_struct *w) if (!delayed_work_pending(dw) && need_update(cpu)) queue_delayed_work_on(cpu, mm_percpu_wq, dw, 0); + + cond_resched(); } put_online_cpus(); -- 2.21.0