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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 BD199C3A5A0 for ; Mon, 19 Aug 2019 22:29:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 900A222CF4 for ; Mon, 19 Aug 2019 22:29:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566253747; bh=gKXjzj2thXw1NrLXTfVBNJCAsAGbw2xe+U3ar2qUAYc=; h=Date:From:To:Subject:List-ID:From; b=OmfZpX4uuLLkxr4o1xsQ85MZBHWO3SHMuX3WA0YcDFQLb5TxioRc8YL2MWfXzUDzX 7MO0uaNyZLJoWFQ/HST/HNbBxath2jo7BhiYkUN82cxYUCIOAL5lSze9hQvVdk2nYr Dtcl4S+lE5551VezJLFCv/zDXfCIho3ENFuud6tk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728538AbfHSW3H (ORCPT ); Mon, 19 Aug 2019 18:29:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:37530 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728438AbfHSW3H (ORCPT ); Mon, 19 Aug 2019 18:29:07 -0400 Received: from akpm3.svl.corp.google.com (unknown [104.133.8.65]) (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 1B93522CE8; Mon, 19 Aug 2019 22:29:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566253746; bh=gKXjzj2thXw1NrLXTfVBNJCAsAGbw2xe+U3ar2qUAYc=; h=Date:From:To:Subject:From; b=DeDzt/wEqzpbGhLxkowof/157SMwVT2OBH+7rVPCtOH7E91iz3v6eOanKG36CSO4u vU6ZQl5yUjAaL6h18BKby6fttbpRUJXG7gtMztvII51yYW47jrNsp8xMmOAj9UF9/9 Wc5bBc8foQ6a5We0r8ZmScDEAqgDHPtZ+6xkBpTU= Date: Mon, 19 Aug 2019 15:29:05 -0700 From: akpm@linux-foundation.org To: mm-commits@vger.kernel.org, vdavydov.dev@gmail.com, stable@vger.kernel.org, mhocko@suse.com, hannes@cmpxchg.org, guro@fb.com Subject: + mm-memcontrol-flush-percpu-vmevents-before-releasing-memcg.patch added to -mm tree Message-ID: <20190819222905.jJDso%akpm@linux-foundation.org> User-Agent: s-nail v14.9.11 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch titled Subject: mm: memcontrol: flush percpu vmevents before releasing memcg has been added to the -mm tree. Its filename is mm-memcontrol-flush-percpu-vmevents-before-releasing-memcg.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-memcontrol-flush-percpu-vmevents-before-releasing-memcg.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-memcontrol-flush-percpu-vmevents-before-releasing-memcg.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Roman Gushchin Subject: mm: memcontrol: flush percpu vmevents before releasing memcg Similar to vmstats, percpu caching of local vmevents leads to an accumulation of errors on non-leaf levels. This happens because some leftovers may remain in percpu caches, so that they are never propagated up by the cgroup tree and just disappear into nonexistence with on releasing of the memory cgroup. To fix this issue let's accumulate and propagate percpu vmevents values before releasing the memory cgroup similar to what we're doing with vmstats. Since on cpu hotplug we do flush percpu vmstats anyway, we can iterate only over online cpus. Link: http://lkml.kernel.org/r/20190819202338.363363-4-guro@fb.com Fixes: 42a300353577 ("mm: memcontrol: fix recursive statistics correctness & scalabilty") Signed-off-by: Roman Gushchin Acked-by: Michal Hocko Cc: Johannes Weiner Cc: Vladimir Davydov Cc: Signed-off-by: Andrew Morton --- mm/memcontrol.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) --- a/mm/memcontrol.c~mm-memcontrol-flush-percpu-vmevents-before-releasing-memcg +++ a/mm/memcontrol.c @@ -3307,6 +3307,25 @@ static void memcg_flush_percpu_vmstats(s } } +static void memcg_flush_percpu_vmevents(struct mem_cgroup *memcg) +{ + unsigned long events[NR_VM_EVENT_ITEMS]; + struct mem_cgroup *mi; + int cpu, i; + + for (i = 0; i < NR_VM_EVENT_ITEMS; i++) + events[i] = 0; + + for_each_online_cpu(cpu) + for (i = 0; i < NR_VM_EVENT_ITEMS; i++) + events[i] += raw_cpu_read( + memcg->vmstats_percpu->events[i]); + + for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) + for (i = 0; i < NR_VM_EVENT_ITEMS; i++) + atomic_long_add(events[i], &mi->vmevents[i]); +} + #ifdef CONFIG_MEMCG_KMEM static int memcg_online_kmem(struct mem_cgroup *memcg) { @@ -4737,10 +4756,11 @@ static void __mem_cgroup_free(struct mem int node; /* - * Flush percpu vmstats to guarantee the value correctness + * Flush percpu vmstats and vmevents to guarantee the value correctness * on parent's and all ancestor levels. */ memcg_flush_percpu_vmstats(memcg, false); + memcg_flush_percpu_vmevents(memcg); for_each_node(node) free_mem_cgroup_per_node_info(memcg, node); free_percpu(memcg->vmstats_percpu); _ Patches currently in -mm which might be from guro@fb.com are mm-memcontrol-flush-percpu-vmstats-before-releasing-memcg.patch mm-memcontrol-flush-percpu-slab-vmstats-on-kmem-offlining.patch mm-memcontrol-flush-percpu-vmevents-before-releasing-memcg.patch mm-memcontrol-switch-to-rcu-protection-in-drain_all_stock.patch