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=-17.4 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 1D0F7C47247 for ; Thu, 30 Apr 2020 18:27:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EF5C0208C3 for ; Thu, 30 Apr 2020 18:27:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="iErXb3iy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726519AbgD3S1v (ORCPT ); Thu, 30 Apr 2020 14:27:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42046 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726309AbgD3S1u (ORCPT ); Thu, 30 Apr 2020 14:27:50 -0400 Received: from mail-vk1-xa49.google.com (mail-vk1-xa49.google.com [IPv6:2607:f8b0:4864:20::a49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 291BEC035495 for ; Thu, 30 Apr 2020 11:27:50 -0700 (PDT) Received: by mail-vk1-xa49.google.com with SMTP id w25so3508182vkm.8 for ; Thu, 30 Apr 2020 11:27:50 -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=Jd1/haHiGLsB9DtO70aA7TDJJ8F7SbAfwTGIrfE2+1I=; b=iErXb3iypgOLBQLKzSmwYHMdYYIq4FQ/Fs5O99JN5OVPg/URrWQYpUpa4kY7FYf/BC XiR39ubKq+M9XC9dm4+/NQtJp45w0zaUOcxMguhS1TnX7J/535wLELSBBjUKWJ1dWqE6 iO6IpODegKvCUHTwKkjF0rYnv7hlPTcyspEUr8iVEgu2zy0g1ZGqrG9JyyK0cqlnx0xy hfdzksqUkq3dN7eAwinITbGyet9pI6lrH090wPE8vGhavh9k/dzJUFPKlX79cfP3D+ls gIS1rabZP18mssvRf0qDpla0A4w7qoWT35CVtPk8OJxUx9mN9fMmyxMODtpX9appu2eY Js8g== 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=Jd1/haHiGLsB9DtO70aA7TDJJ8F7SbAfwTGIrfE2+1I=; b=FvB5+sP3nW6Vo2tA+SkBx2U05P2pOv2cIXsDMQxqTxSVgVlhC5z9kjlx6A+aoNU/F9 5gREZBOdUWZ0p75LxiVPOgqRKdG03X3eRT2xnPpC6o+DIUNxU695lZmKVUa6xiLJM/VB 9HhQcW06YtOXX4sv/d8KmaEP3LVQt5ZZ6ClDWIzP+NQgPVVCuhAqP+6D5o1xTdLISmcU IZ7kes2GVUNiGPbvmpNaiIhrU597rApypq7FT2JavPKEqqI8e/MXN4Zflp4AgCZCMNfF 7M5NBfAgEuQMfeMIArL989t3SJucY7d6sDZCWuIU4SCyg9mZQwZGAZV+WE/5U9JdQivn vNog== X-Gm-Message-State: AGi0PuZJFGpkobcESfoez3X1gLNxIWWljMhlxseHLZ3BaoUlYHL79yQM 8HkReliLRm+d4R4jzkXKoxWR7izQJ9GuHA== X-Google-Smtp-Source: APiQypIJnnUciZumXRHEJORNQcdjcnFEMXOXdpW+p2iyl9bRjHAlZXre3Ldi7KIlBZPqLSNMvedoctuZFZ1Xag== X-Received: by 2002:a9f:2188:: with SMTP id 8mr8788uac.46.1588271269078; Thu, 30 Apr 2020 11:27:49 -0700 (PDT) Date: Thu, 30 Apr 2020 11:27:12 -0700 Message-Id: <20200430182712.237526-1-shakeelb@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.26.2.526.g744177e7f7-goog Subject: [PATCH] memcg: oom: ignore oom warnings from memory.max From: Shakeel Butt To: Johannes Weiner , Roman Gushchin , Michal Hocko Cc: Greg Thelen , Andrew Morton , 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 Lowering memory.max can trigger an oom-kill if the reclaim does not succeed. However if oom-killer does not find a process for killing, it dumps a lot of warnings. Deleting a memcg does not reclaim memory from it and the memory can linger till there is a memory pressure. One normal way to proactively reclaim such memory is to set memory.max to 0 just before deleting the memcg. However if some of the memcg's memory is pinned by others, this operation can trigger an oom-kill without any process and thus can log a lot un-needed warnings. So, ignore all such warnings from memory.max. Signed-off-by: Shakeel Butt --- include/linux/oom.h | 3 +++ mm/memcontrol.c | 9 +++++---- mm/oom_kill.c | 2 +- 3 files changed, 9 insertions(+), 5 deletions(-) diff --git a/include/linux/oom.h b/include/linux/oom.h index c696c265f019..6345dc55df64 100644 --- a/include/linux/oom.h +++ b/include/linux/oom.h @@ -52,6 +52,9 @@ struct oom_control { /* Used to print the constraint info. */ enum oom_constraint constraint; + + /* Do not warn even if there is no process to be killed. */ + bool no_warn; }; extern struct mutex oom_lock; diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 317dbbaac603..a1f00d9b9bb0 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1571,7 +1571,7 @@ unsigned long mem_cgroup_size(struct mem_cgroup *memcg) } static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, - int order) + int order, bool no_warn) { struct oom_control oc = { .zonelist = NULL, @@ -1579,6 +1579,7 @@ static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, .memcg = memcg, .gfp_mask = gfp_mask, .order = order, + .no_warn = no_warn, }; bool ret; @@ -1821,7 +1822,7 @@ static enum oom_status mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int mem_cgroup_oom_notify(memcg); mem_cgroup_unmark_under_oom(memcg); - if (mem_cgroup_out_of_memory(memcg, mask, order)) + if (mem_cgroup_out_of_memory(memcg, mask, order, false)) ret = OOM_SUCCESS; else ret = OOM_FAILED; @@ -1880,7 +1881,7 @@ bool mem_cgroup_oom_synchronize(bool handle) mem_cgroup_unmark_under_oom(memcg); finish_wait(&memcg_oom_waitq, &owait.wait); mem_cgroup_out_of_memory(memcg, current->memcg_oom_gfp_mask, - current->memcg_oom_order); + current->memcg_oom_order, false); } else { schedule(); mem_cgroup_unmark_under_oom(memcg); @@ -6106,7 +6107,7 @@ static ssize_t memory_max_write(struct kernfs_open_file *of, } memcg_memory_event(memcg, MEMCG_OOM); - if (!mem_cgroup_out_of_memory(memcg, GFP_KERNEL, 0)) + if (!mem_cgroup_out_of_memory(memcg, GFP_KERNEL, 0, true)) break; } diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 463b3d74a64a..5ace39f6fe1e 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -1098,7 +1098,7 @@ bool out_of_memory(struct oom_control *oc) select_bad_process(oc); /* Found nothing?!?! */ - if (!oc->chosen) { + if (!oc->chosen && !oc->no_warn) { dump_header(oc, NULL); pr_warn("Out of memory and no killable processes...\n"); /* -- 2.26.2.526.g744177e7f7-goog