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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 25D5DC433DB for ; Fri, 26 Feb 2021 01:16:58 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A035664F10 for ; Fri, 26 Feb 2021 01:16:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A035664F10 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 3B7C06B006C; Thu, 25 Feb 2021 20:16:57 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 33E136B006E; Thu, 25 Feb 2021 20:16:57 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 27A626B0070; Thu, 25 Feb 2021 20:16:57 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0076.hostedemail.com [216.40.44.76]) by kanga.kvack.org (Postfix) with ESMTP id 10A2F6B006C for ; Thu, 25 Feb 2021 20:16:57 -0500 (EST) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id D1B2CC5D0 for ; Fri, 26 Feb 2021 01:16:56 +0000 (UTC) X-FDA: 77858654832.22.1F7C1D3 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf16.hostedemail.com (Postfix) with ESMTP id D1DF480192E4 for ; Fri, 26 Feb 2021 01:16:55 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 2518064F13; Fri, 26 Feb 2021 01:16:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1614302215; bh=aERu7B+meUjS1DkaQS6FJmelVfnIKPgjL4xkn8mlZps=; h=Date:From:To:Subject:In-Reply-To:From; b=h2wVN3HuHinsxkkc8J580tB8AfyKbORrRKdsBG+FmPI5ub3WMY91YezHdnXWgp9mL wNPd0q0EXHWEmSGwzkyM3WA8labhSW1RsAtAgVTEEXM6N0ugd5uXXFl81iHvxDJ4LU Zh7Uifm1yMwhrLnK7Bgh0v/A4QdCIHnc8U2AlmuQ= Date: Thu, 25 Feb 2021 17:16:54 -0800 From: Andrew Morton To: akpm@linux-foundation.org, benbjiang@tencent.com, cl@linux-foundation.org, linux-mm@kvack.org, mm-commits@vger.kernel.org, robinlai@tencent.com, torvalds@linux-foundation.org Subject: [patch 025/118] mm/vmstat.c: erase latency in vmstat_shepherd Message-ID: <20210226011654.UO7WPPOjW%akpm@linux-foundation.org> In-Reply-To: <20210225171452.713967e96554bb6a53e44a19@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: D1DF480192E4 X-Stat-Signature: maqoqec79pw1pd5qmm5aani9pbp3g13z Received-SPF: none (linux-foundation.org>: No applicable sender policy available) receiver=imf16; identity=mailfrom; envelope-from=""; helo=mail.kernel.org; client-ip=198.145.29.99 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614302215-215147 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Jiang Biao Subject: mm/vmstat.c: erase latency in vmstat_shepherd 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. Link: https://lkml.kernel.org/r/20210111035526.1511-1-benbjiang@tencent.com Signed-off-by: Jiang Biao Reported-by: Bin Lai Cc: Christoph Lameter Signed-off-by: Andrew Morton --- mm/vmstat.c | 2 ++ 1 file changed, 2 insertions(+) --- a/mm/vmstat.c~mm-vmstatc-erase-latency-in-vmstat_shepherd +++ a/mm/vmstat.c @@ -1980,6 +1980,8 @@ static void vmstat_shepherd(struct work_ if (!delayed_work_pending(dw) && need_update(cpu)) queue_delayed_work_on(cpu, mm_percpu_wq, dw, 0); + + cond_resched(); } put_online_cpus(); _