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=-16.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL 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 30DA7C46470 for ; Fri, 17 May 2019 23:49:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EB4DA21726 for ; Fri, 17 May 2019 23:49:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Bvr6EX1B" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727439AbfEQXtU (ORCPT ); Fri, 17 May 2019 19:49:20 -0400 Received: from mail-yw1-f73.google.com ([209.85.161.73]:34821 "EHLO mail-yw1-f73.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726200AbfEQXtU (ORCPT ); Fri, 17 May 2019 19:49:20 -0400 Received: by mail-yw1-f73.google.com with SMTP id r23so7899737ywg.2 for ; Fri, 17 May 2019 16:49:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=A7gs1+mF+FP/rGmpwnYONHmDSeyLtKWRbITND9nfmUM=; b=Bvr6EX1BZXsucquzdYD7Uqmbj6wwCOxg3rcQn60MXW4DU7nJ6/r0BcLbdwz5tSoo77 t8gK6+Z8fzNWaCdetWoEM7f+2o8RnbLx8CS1YTx0OWWOXgHf9GbSSna8rk7ZkJtW9366 qbOsVKy8h934mTsg17ZQzmg23y3wZf6pC6xq1BVMNnUuFeutN/8AR5EEbmK2sMuprJRg a6emrfrio99QVrVPAotorRVenxbKFArMXtlR5cm7+deloUaXTiqoqlTSpS4oeX0kgREi 0grH9KoxLi4uE2v2hT9u5ceJ8cARpo0zsvhoqwkeDP3WrpIcGPvl6wRM7wSZypUbnFbe t2WA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=A7gs1+mF+FP/rGmpwnYONHmDSeyLtKWRbITND9nfmUM=; b=F2XppEuHgDGHGRHx/VCKnMEvTIk1fCbQs5UT3TDUj1Dh5q8InwZtPmhJMy1t3gpXKH v3elyN5CLf9FmP2J8tV3265V5oaQZv79eqm8TJUvcabMTof5+iuk1RKTfGgJcP/KjQjX 19/LaTZ2W3s6dhzC7LWSXJVPM5nMbTsWy7Dzcwj8PIkaetB6D0AtqZ+74DDd5rCQxQ1x j8PVOA+wQmsGZNqIGqUTZTjd5zhguJl1UJmpq4pcfmeuS4EJwMeXq9vE5rFM1//Qpdoo fCKRh9ROkr8TXv65HZrqG9MqTy/70w9b0K9F+HQEtCWAFFYn9taVBOthOuDB3/kC9kpt Pq9Q== X-Gm-Message-State: APjAAAX20kVpTTGtZVkugxqB/nNG5M9KdVMXyIP20nq0UIVI9dTfmIBU sHLcBm0sJeCqG4wkAqSb9Kn02+dHcA4OBQ== X-Google-Smtp-Source: APXvYqwKEww9mPrrXsrI0/TpLKrEc7pSe78bah2w5Z+0kdvcu66zLeplA2OTybD6hUGaqQkHasrvoaOkRdan0w== X-Received: by 2002:a81:3589:: with SMTP id c131mr28332892ywa.456.1558136959229; Fri, 17 May 2019 16:49:19 -0700 (PDT) Date: Fri, 17 May 2019 16:49:09 -0700 Message-Id: <20190517234909.175734-1-shakeelb@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.21.0.1020.gf2820cf01a-goog Subject: [PATCH] mm, memcg: introduce memory.events.local From: Shakeel Butt To: Johannes Weiner , Vladimir Davydov , Michal Hocko , Andrew Morton , Roman Gushchin , Chris Down Cc: linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Shakeel Butt Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The memory controller in cgroup v2 exposes memory.events file for each memcg which shows the number of times events like low, high, max, oom and oom_kill have happened for the whole tree rooted at that memcg. Users can also poll or register notification to monitor the changes in that file. Any event at any level of the tree rooted at memcg will notify all the listeners along the path till root_mem_cgroup. There are existing users which depend on this behavior. However there are users which are only interested in the events happening at a specific level of the memcg tree and not in the events in the underlying tree rooted at that memcg. One such use-case is a centralized resource monitor which can dynamically adjust the limits of the jobs running on a system. The jobs can create their sub-hierarchy for their own sub-tasks. The centralized monitor is only interested in the events at the top level memcgs of the jobs as it can then act and adjust the limits of the jobs. Using the current memory.events for such centralized monitor is very inconvenient. The monitor will keep receiving events which it is not interested and to find if the received event is interesting, it has to read memory.event files of the next level and compare it with the top level one. So, let's introduce memory.events.local to the memcg which shows and notify for the events at the memcg level. Now, does memory.stat and memory.pressure need their local versions. IMHO no due to the no internal process contraint of the cgroup v2. The memory.stat file of the top level memcg of a job shows the stats and vmevents of the whole tree. The local stats or vmevents of the top level memcg will only change if there is a process running in that memcg but v2 does not allow that. Similarly for memory.pressure there will not be any process in the internal nodes and thus no chance of local pressure. Signed-off-by: Shakeel Butt --- include/linux/memcontrol.h | 7 ++++++- mm/memcontrol.c | 25 +++++++++++++++++++++++++ 2 files changed, 31 insertions(+), 1 deletion(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 36bdfe8e5965..de77405eec46 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -239,8 +239,9 @@ struct mem_cgroup { /* OOM-Killer disable */ int oom_kill_disable; - /* memory.events */ + /* memory.events and memory.events.local */ struct cgroup_file events_file; + struct cgroup_file events_local_file; /* handle for "memory.swap.events" */ struct cgroup_file swap_events_file; @@ -286,6 +287,7 @@ struct mem_cgroup { atomic_long_t vmevents_local[NR_VM_EVENT_ITEMS]; atomic_long_t memory_events[MEMCG_NR_MEMORY_EVENTS]; + atomic_long_t memory_events_local[MEMCG_NR_MEMORY_EVENTS]; unsigned long socket_pressure; @@ -761,6 +763,9 @@ static inline void count_memcg_event_mm(struct mm_struct *mm, static inline void memcg_memory_event(struct mem_cgroup *memcg, enum memcg_memory_event event) { + atomic_long_inc(&memcg->memory_events_local[event]); + cgroup_file_notify(&memcg->events_local_file); + do { atomic_long_inc(&memcg->memory_events[event]); cgroup_file_notify(&memcg->events_file); diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 2713b45ec3f0..a746127012fa 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5648,6 +5648,25 @@ static int memory_events_show(struct seq_file *m, void *v) return 0; } +static int memory_events_local_show(struct seq_file *m, void *v) +{ + struct mem_cgroup *memcg = mem_cgroup_from_seq(m); + + seq_printf(m, "low %lu\n", + atomic_long_read(&memcg->memory_events_local[MEMCG_LOW])); + seq_printf(m, "high %lu\n", + atomic_long_read(&memcg->memory_events_local[MEMCG_HIGH])); + seq_printf(m, "max %lu\n", + atomic_long_read(&memcg->memory_events_local[MEMCG_MAX])); + seq_printf(m, "oom %lu\n", + atomic_long_read(&memcg->memory_events_local[MEMCG_OOM])); + seq_printf(m, "oom_kill %lu\n", + atomic_long_read(&memcg->memory_events_local[MEMCG_OOM_KILL]) + ); + + return 0; +} + static int memory_stat_show(struct seq_file *m, void *v) { struct mem_cgroup *memcg = mem_cgroup_from_seq(m); @@ -5806,6 +5825,12 @@ static struct cftype memory_files[] = { .file_offset = offsetof(struct mem_cgroup, events_file), .seq_show = memory_events_show, }, + { + .name = "events.local", + .flags = CFTYPE_NOT_ON_ROOT, + .file_offset = offsetof(struct mem_cgroup, events_local_file), + .seq_show = memory_events_local_show, + }, { .name = "stat", .flags = CFTYPE_NOT_ON_ROOT, -- 2.21.0.1020.gf2820cf01a-goog