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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 25C6EC433EF for ; Thu, 24 Mar 2022 18:17:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352578AbiCXSSx (ORCPT ); Thu, 24 Mar 2022 14:18:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33774 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352575AbiCXSSv (ORCPT ); Thu, 24 Mar 2022 14:18:51 -0400 Received: from out1.migadu.com (out1.migadu.com [91.121.223.63]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2D361B7170; Thu, 24 Mar 2022 11:17:19 -0700 (PDT) Content-Type: text/plain; charset=utf-8 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1648145837; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+Xdg6AguU1tCjET4IpuuuOj6DcGbMJAnyZKDx5p9X6o=; b=CaznleEkIgnUPwdpezvS7Q1Z4Lx0QM+qd453HpZhRxWImtUouqJZERSIMyPP1D2gE8ZEgK hunDJ2I4gzVQNoBZ4dAQD8M976MYphFJnDpz5hcIVyr8TlmscQS2WpsWbWgfK1i5SJvIAc 0p6Mq5sqgguQ1ED1eaSfq88c1oCQ5Go= Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [RFC PATCH] mm: memcg: Do not count memory.low reclaim if it does not happen X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Roman Gushchin In-Reply-To: <20220324095157.GA16685@blackbody.suse.cz> Date: Thu, 24 Mar 2022 11:17:14 -0700 Cc: cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Richard Palethorpe , Andrew Morton , Shakeel Butt , Michal Hocko , Vlastimil Babka , "Matthew Wilcox (Oracle)" , Muchun Song , Johannes Weiner , Yang Shi , Suren Baghdasaryan , Tejun Heo , Chris Down Message-Id: <5049EBC3-5BAE-4509-BA63-1F4A7D913517@linux.dev> References: <20220324095157.GA16685@blackbody.suse.cz> To: =?utf-8?Q?Michal_Koutn=C3=BD?= X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Mar 24, 2022, at 2:52 AM, Michal Koutn=C3=BD wrote: >=20 > =EF=BB=BFOn Wed, Mar 23, 2022 at 02:44:24PM -0700, Roman Gushchin wrote: >> Does it mean that in the following configuration: >> `parent .low=3D50M >> ` s1 .low=3D0M .current=3D50M >> ` s2 .low=3D0M .current=3D50M >> there will be no memory.events::low at all? (assuming the recursive thing= is on) >=20 > True, no memory.events:low among siblings. > Number of memory.events:low in the parent depends on how much has to be > reclaimed (>50M means carving into parent's protection, hence it'll be > counted). Ok, so it=E2=80=99s not really about the implementation details of the recla= im mechanism (I mean rounding up to the batch size etc), it=E2=80=99s a more= generic change: do not generate low events for cgroups not explicitly prote= cted by a non-zero memory.low value. Idk, I don=E2=80=99t have a strong argument against this change (except that= it changes the existing behavior), but I also don=E2=80=99t see why such ev= ents are harmful. Do you mind elaborating a bit more? Thank you!=