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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,URIBL_SBL,URIBL_SBL_A, USER_AGENT_GIT autolearn=unavailable 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 9747AC433FF for ; Mon, 5 Aug 2019 13:23:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6802A20880 for ; Mon, 5 Aug 2019 13:23:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565011422; bh=8uCq6Hog5rSLXya+/nTvcvv2RE/+H2+vXoQZB/KOLes=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wtsJBbTRluiL405uFIHWPt1WrvkUddyCm5aUMu09kDX0e3EqU9as0IdUyI7vb3I64 iky4ZEK9lxiwzw6YQrwNhrvYsCV8l7eeMGuZPn0UjJR/TFYYumDUhtSbrE2vv5guGd KhG7XFJABR0Bt9HnFewRfse4B4Xb57itYzygh6JA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730585AbfHENXk (ORCPT ); Mon, 5 Aug 2019 09:23:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:60356 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730858AbfHENXh (ORCPT ); Mon, 5 Aug 2019 09:23:37 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 293F221880; Mon, 5 Aug 2019 13:23:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565011416; bh=8uCq6Hog5rSLXya+/nTvcvv2RE/+H2+vXoQZB/KOLes=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BCtQaIzodfI8jEbOZRiaI53O16daspKgrsG+GfLcdlpYjW/HiVPOA7jbYq+RJtvOJ +ZKEz8SmzwjiK1tKlbUdwQRU4IqTPQpc88XiJrP3zP+6ktpjufuK9DeziSvVH0JM29 JRk+1cPMRsSFN6tLElk8bC/KvSNUhpJ9JsGAm2JE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yafang Shao , Johannes Weiner , Michal Hocko , Vladimir Davydov , Yafang Shao , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH 5.2 049/131] mm/memcontrol.c: keep local VM counters in sync with the hierarchical ones Date: Mon, 5 Aug 2019 15:02:16 +0200 Message-Id: <20190805124954.714867980@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190805124951.453337465@linuxfoundation.org> References: <20190805124951.453337465@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit 766a4c19d880887c457811b86f1f68525e416965 ] After commit 815744d75152 ("mm: memcontrol: don't batch updates of local VM stats and events"), the local VM counter are not in sync with the hierarchical ones. Below is one example in a leaf memcg on my server (with 8 CPUs): inactive_file 3567570944 total_inactive_file 3568029696 We find that the deviation is very great because the 'val' in __mod_memcg_state() is in pages while the effective value in memcg_stat_show() is in bytes. So the maximum of this deviation between local VM stats and total VM stats can be (32 * number_of_cpu * PAGE_SIZE), that may be an unacceptably great value. We should keep the local VM stats in sync with the total stats. In order to keep this behavior the same across counters, this patch updates __mod_lruvec_state() and __count_memcg_events() as well. Link: http://lkml.kernel.org/r/1562851979-10610-1-git-send-email-laoar.shao@gmail.com Signed-off-by: Yafang Shao Acked-by: Johannes Weiner Cc: Michal Hocko Cc: Vladimir Davydov Cc: Yafang Shao Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- mm/memcontrol.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 591eafafbd8cb..902d020aa70e5 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -691,12 +691,15 @@ void __mod_memcg_state(struct mem_cgroup *memcg, int idx, int val) if (mem_cgroup_disabled()) return; - __this_cpu_add(memcg->vmstats_local->stat[idx], val); - x = val + __this_cpu_read(memcg->vmstats_percpu->stat[idx]); if (unlikely(abs(x) > MEMCG_CHARGE_BATCH)) { struct mem_cgroup *mi; + /* + * Batch local counters to keep them in sync with + * the hierarchical ones. + */ + __this_cpu_add(memcg->vmstats_local->stat[idx], x); for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) atomic_long_add(x, &mi->vmstats[idx]); x = 0; @@ -745,13 +748,15 @@ void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, /* Update memcg */ __mod_memcg_state(memcg, idx, val); - /* Update lruvec */ - __this_cpu_add(pn->lruvec_stat_local->count[idx], val); - x = val + __this_cpu_read(pn->lruvec_stat_cpu->count[idx]); if (unlikely(abs(x) > MEMCG_CHARGE_BATCH)) { struct mem_cgroup_per_node *pi; + /* + * Batch local counters to keep them in sync with + * the hierarchical ones. + */ + __this_cpu_add(pn->lruvec_stat_local->count[idx], x); for (pi = pn; pi; pi = parent_nodeinfo(pi, pgdat->node_id)) atomic_long_add(x, &pi->lruvec_stat[idx]); x = 0; @@ -773,12 +778,15 @@ void __count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx, if (mem_cgroup_disabled()) return; - __this_cpu_add(memcg->vmstats_local->events[idx], count); - x = count + __this_cpu_read(memcg->vmstats_percpu->events[idx]); if (unlikely(x > MEMCG_CHARGE_BATCH)) { struct mem_cgroup *mi; + /* + * Batch local counters to keep them in sync with + * the hierarchical ones. + */ + __this_cpu_add(memcg->vmstats_local->events[idx], x); for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) atomic_long_add(x, &mi->vmevents[idx]); x = 0; -- 2.20.1