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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E499C433EF for ; Thu, 17 Feb 2022 14:45:29 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B66756B0074; Thu, 17 Feb 2022 09:45:28 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id B164E6B0075; Thu, 17 Feb 2022 09:45:28 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9DEA16B0078; Thu, 17 Feb 2022 09:45:28 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.27]) by kanga.kvack.org (Postfix) with ESMTP id 9126B6B0074 for ; Thu, 17 Feb 2022 09:45:28 -0500 (EST) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay11.hostedemail.com (Postfix) with ESMTP id 5A7C6801BD for ; Thu, 17 Feb 2022 14:45:28 +0000 (UTC) X-FDA: 79152545136.01.AB67528 Received: from p3plsmtpa11-04.prod.phx3.secureserver.net (p3plsmtpa11-04.prod.phx3.secureserver.net [68.178.252.105]) by imf27.hostedemail.com (Postfix) with ESMTP id AE4D040007 for ; Thu, 17 Feb 2022 14:45:27 +0000 (UTC) Received: from localhost ([82.17.115.212]) by :SMTPAUTH: with ESMTPA id Ki28n316uQeWgKi2AnNP8p; Thu, 17 Feb 2022 07:45:26 -0700 X-CMAE-Analysis: v=2.4 cv=Fa7yeLy6 c=1 sm=1 tr=0 ts=620e5f86 a=9gipVNR6X1CoIeAWHwLoWw==:117 a=9gipVNR6X1CoIeAWHwLoWw==:17 a=IkcTkHD0fZMA:10 a=r5m66G8ZfA9aYF3hFTkA:9 a=QEXdDO2ut3YA:10 X-SECURESERVER-ACCT: atomlin@atomlin.com Date: Thu, 17 Feb 2022 14:45:24 +0000 From: Aaron Tomlin To: Frederic Weisbecker Cc: Aaron Tomlin , Phil Auld , tglx@linutronix.de, mingo@kernel.org, mingo@redhat.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC PATCH] tick/sched: Ensure quiet_vmstat() is called when the idle tick was stopped too Message-ID: <20220217144524.el7lwi45hwsf3ef2@ava.usersys.com> References: <20220203214339.1889971-1-atomlin@redhat.com> <20220216143412.dwxjlkq4w2zeweld@ava.usersys.com> <20220217125731.GA744754@lothringen> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220217125731.GA744754@lothringen> X-CMAE-Envelope: MS4xfLkWofOShUPdAv6/WMzdpwZTNw5VpOKWtXuAJawWtOZ7Rms7HwLXEwraAp/eqA7/7AcSC81edXfGXBhmpxJxyhkrNwi8JMZRHFXhuQv1hiJ/0kYhTy/s +aiknQJNXvx3+KiX+0CNIC/8IxRsRwn304CHwtTt4ve0Ibe1yRsLxlw4Mq6OsaJdpiaY6f8B+8sbtlGF22V+TvCV4CzAQkJj3TnbwLk0nhdYAFHZZPR9WK+/ tiZMQtciczwUoiGX9bs7RT+SyHqtzqIM/3VGnGDM2rGT71izV3WzdTE8queJ5ZTEC8jZ/U00jUXQHehO8cMl+D7czfcG74hFNh1Yw601RSWoNNsI8DNa8Z5D trS24NvvmF28cVGHalXRjNIOPWrVQvANrFO/vZf4VAALog3qGeM= X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: AE4D040007 X-Stat-Signature: sf1ywhp6op5nh15gui3t5mqbn1wd3khm X-Rspam-User: Authentication-Results: imf27.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf27.hostedemail.com: domain of atomlin@atomlin.com designates 68.178.252.105 as permitted sender) smtp.mailfrom=atomlin@atomlin.com X-HE-Tag: 1645109127-955577 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: On Thu 2022-02-17 13:57 +0100, Frederic Weisbecker wrote: > Hmm, but does it matter? The issue seem to be that we can enter in idle loop without > flushing vmstat. Or am I missing something else? Frederic, Yes, this is indeed the concern. So, the idea I had was to invoke quiet_vmstat() regardless if the tick was stopped or not. If I understand correctly, this should resolve the issue. Furthermore, folding of all outstanding differentials will only occur when required. Thus performance should be negligible. Kind regards, -- Aaron Tomlin