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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 EF258C282E1 for ; Thu, 25 Apr 2019 06:49:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BBD45217FA for ; Thu, 25 Apr 2019 06:49:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556174941; bh=MFo2rs2Ksm6iIGTkbw6Qnp6OfwD7vUc2eJoOI9F2Diw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=nr5/8Qz+tW8puXKoCLV31t7uFk6cyLiRefWTFcxMpK76VTuepDoxPRZGGFm0DahQr ynM4W841vv61phFN2cR6QD0CaJzhTpSDZMHAzmZngxaUF7+NP4cdm7x8AhZyXQHXtd 08miIpscbHuGH56pHqgnz1il3bAIsdi5Ta4EtyVs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388049AbfDYGtA (ORCPT ); Thu, 25 Apr 2019 02:49:00 -0400 Received: from mx2.suse.de ([195.135.220.15]:57804 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725970AbfDYGtA (ORCPT ); Thu, 25 Apr 2019 02:49:00 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 0BE0DABF4; Thu, 25 Apr 2019 06:48:59 +0000 (UTC) Date: Thu, 25 Apr 2019 08:48:58 +0200 From: Michal Hocko To: Shakeel Butt Cc: Johannes Weiner , Vladimir Davydov , Andrew Morton , Roman Gushchin , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] memcg: refill_stock for kmem uncharging too Message-ID: <20190425064858.GL12751@dhcp22.suse.cz> References: <20190423154405.259178-1-shakeelb@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190423154405.259178-1-shakeelb@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 23-04-19 08:44:05, Shakeel Butt wrote: > The commit 475d0487a2ad ("mm: memcontrol: use per-cpu stocks for socket > memory uncharging") added refill_stock() for skmem uncharging path to > optimize workloads having high network traffic. Do the same for the kmem > uncharging as well. Though we can bypass the refill for the offlined > memcgs but it may impact the performance of network traffic for the > sockets used by other cgroups. While the change makes sense, I would really like to see what kind of effect on performance does it really have. Do you have any specific workload that benefits from it? Thanks! > Signed-off-by: Shakeel Butt > Cc: Roman Gushchin > Cc: Johannes Weiner > Cc: Michal Hocko > Cc: Vladimir Davydov > Cc: Andrew Morton > --- > > Changelog since v1: > - No need to bypass offline memcgs in the refill. > > mm/memcontrol.c | 6 +----- > 1 file changed, 1 insertion(+), 5 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 2535e54e7989..2713b45ec3f0 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -2768,17 +2768,13 @@ void __memcg_kmem_uncharge(struct page *page, int order) > if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) > page_counter_uncharge(&memcg->kmem, nr_pages); > > - page_counter_uncharge(&memcg->memory, nr_pages); > - if (do_memsw_account()) > - page_counter_uncharge(&memcg->memsw, nr_pages); > - > page->mem_cgroup = NULL; > > /* slab pages do not have PageKmemcg flag set */ > if (PageKmemcg(page)) > __ClearPageKmemcg(page); > > - css_put_many(&memcg->css, nr_pages); > + refill_stock(memcg, nr_pages); > } > #endif /* CONFIG_MEMCG_KMEM */ > > -- > 2.21.0.593.g511ec345e18-goog > -- Michal Hocko SUSE Labs