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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 DBE88C433E6 for ; Wed, 10 Feb 2021 00:53:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 983E264E66 for ; Wed, 10 Feb 2021 00:53:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234808AbhBJAwr (ORCPT ); Tue, 9 Feb 2021 19:52:47 -0500 Received: from mga12.intel.com ([192.55.52.136]:8467 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231395AbhBIWLG (ORCPT ); Tue, 9 Feb 2021 17:11:06 -0500 IronPort-SDR: BqpNjUBAt8Oeg9Z+FKo5kPTGcpnKBMsxBkM7iaBfZ+l0zWn8t7z6+k9kPWIXCAugjKbep0wZzX VBCiYTTBsWcw== X-IronPort-AV: E=McAfee;i="6000,8403,9890"; a="161113142" X-IronPort-AV: E=Sophos;i="5.81,166,1610438400"; d="scan'208";a="161113142" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Feb 2021 13:30:34 -0800 IronPort-SDR: LudR3XWil918DSthPWyyBqoO8EWHAOIRC8WyvaRhVpXmHic1CIkS6jcfhCD68569+SMYdn4DS/ xKcXcqLESlDQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.81,166,1610438400"; d="scan'208";a="361953013" Received: from skl-02.jf.intel.com ([10.54.74.28]) by orsmga006.jf.intel.com with ESMTP; 09 Feb 2021 13:30:34 -0800 From: Tim Chen To: Andrew Morton , Johannes Weiner , Michal Hocko , Vladimir Davydov Cc: Tim Chen , Dave Hansen , Ying Huang , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/3] mm: Fix dropped memcg from mem cgroup soft limit tree Date: Tue, 9 Feb 2021 12:29:45 -0800 Message-Id: X-Mailer: git-send-email 2.20.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org During soft limit memory reclaim, we will temporarily remove the target mem cgroup from the cgroup soft limit tree. We then perform memory reclaim, update the memory usage excess count and re-insert the mem cgroup back into the mem cgroup soft limit tree according to the new memory usage excess count. However, when memory reclaim failed for a maximum number of attempts and we bail out of the reclaim loop, we forgot to put the target mem cgroup chosen for next reclaim back to the soft limit tree. This prevented pages in the mem cgroup from being reclaimed in the future even though the mem cgroup exceeded its soft limit. Fix the logic and put the mem cgroup back on the tree when page reclaim failed for the mem cgroup. Reviewed-by: Ying Huang Signed-off-by: Tim Chen --- mm/memcontrol.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index ed5cc78a8dbf..a51bf90732cb 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3505,8 +3505,12 @@ unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order, loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) break; } while (!nr_reclaimed); - if (next_mz) + if (next_mz) { + spin_lock_irq(&mctz->lock); + __mem_cgroup_insert_exceeded(next_mz, mctz, excess); + spin_unlock_irq(&mctz->lock); css_put(&next_mz->memcg->css); + } return nr_reclaimed; } -- 2.20.1