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=-9.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 2219CC7618B for ; Fri, 26 Jul 2019 13:41:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EA9E422C7E for ; Fri, 26 Jul 2019 13:41:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564148469; bh=kL3mlcYcc+Q9jAb4Pl1atYrXYmTb6HeWN92nUpHLk3A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Hs2yffOgmws1pef/duXK634ybnPkNpsvwW0dGXmpbyi7hsD74JrDuswkUYWS/T9fA kP2B+2fCiRf4gKr9u8XyH5oIrY6q7OlfdMLOXdJ216JR+rUR2db6yNSvhmtkGRaPgI Vrfle7f1jXB58+1aBzygfCpgJ7+fNR5mb5LSuGM8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727823AbfGZNlH (ORCPT ); Fri, 26 Jul 2019 09:41:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:47304 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727260AbfGZNlB (ORCPT ); Fri, 26 Jul 2019 09:41:01 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 935C122CD5; Fri, 26 Jul 2019 13:40:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564148459; bh=kL3mlcYcc+Q9jAb4Pl1atYrXYmTb6HeWN92nUpHLk3A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Fw6HTIlJ+dAqBanjdLDnU16zhOoRdqUtIylBtdNW2WzzF5FvL2Cx8vuj8jhqG1j9M M3B+u6aLF4Gk3rzzT/VYncTazb8cwYNb5xdX3nivM5JTBdyB7WLV2x2rmt8R/F2hxY U7BmMX8rV2rgejZsHmQ2yjPpYzbhRRGaDk4MvuHs= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Yafang Shao , Johannes Weiner , Michal Hocko , Vladimir Davydov , Yafang Shao , Andrew Morton , Linus Torvalds , Sasha Levin , cgroups@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH AUTOSEL 5.2 52/85] mm/memcontrol.c: keep local VM counters in sync with the hierarchical ones Date: Fri, 26 Jul 2019 09:39:02 -0400 Message-Id: <20190726133936.11177-52-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190726133936.11177-1-sashal@kernel.org> References: <20190726133936.11177-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Yafang Shao [ 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 ba9138a4a1de..07b4ca559bcc 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