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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 8113DC433E0 for ; Fri, 29 May 2020 01:06:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 648E7206E2 for ; Fri, 29 May 2020 01:06:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2438323AbgE2BG3 (ORCPT ); Thu, 28 May 2020 21:06:29 -0400 Received: from mga17.intel.com ([192.55.52.151]:2379 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2438312AbgE2BG0 (ORCPT ); Thu, 28 May 2020 21:06:26 -0400 IronPort-SDR: kEIJMm9qel9FpjkjNRI67hhCsolEkE/+RvGPxcZiWGUB+ae7HndrRjOToI0ftzD6usWzih2Hej OwoOf4NitAag== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 May 2020 18:06:26 -0700 IronPort-SDR: t9036NUhHUGwWveLlQIds2EuWb519n1VXvhfA4Y1WdfrsMoWv1eWHhzwMauuq1L5xjXAGhainG 8jkg7yyatc3A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,446,1583222400"; d="scan'208";a="443187421" Received: from shbuild999.sh.intel.com ([10.239.146.107]) by orsmga005.jf.intel.com with ESMTP; 28 May 2020 18:06:22 -0700 From: Feng Tang To: Andrew Morton , Michal Hocko , Johannes Weiner , Matthew Wilcox , Mel Gorman , Kees Cook , Qian Cai , andi.kleen@intel.com, tim.c.chen@intel.com, dave.hansen@intel.com, ying.huang@intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Feng Tang , Konstantin Khlebnikov Subject: [PATCH v4 3/4] mm/util.c: remove the VM_WARN_ONCE for vm_committed_as underflow check Date: Fri, 29 May 2020 09:06:09 +0800 Message-Id: <1590714370-67182-4-git-send-email-feng.tang@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1590714370-67182-1-git-send-email-feng.tang@intel.com> References: <1590714370-67182-1-git-send-email-feng.tang@intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org As is explained by Michal Hocko: : Looking at the history, this has been added by 82f71ae4a2b8 : ("mm: catch memory commitment underflow") to have a safety check : for issues which have been fixed. There doesn't seem to be any bug : reports mentioning this splat since then so it is likely just : spending cycles for a hot path (yes many people run with DEBUG_VM) : without a strong reason. Signed-off-by: Feng Tang Cc: Konstantin Khlebnikov Cc: Qian Cai Cc: Michal Hocko Cc: Andi Kleen --- mm/util.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/mm/util.c b/mm/util.c index 3c7a08c..fe63271 100644 --- a/mm/util.c +++ b/mm/util.c @@ -814,14 +814,6 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) { long allowed; - /* - * A transient decrease in the value is unlikely, so no need - * READ_ONCE() for vm_committed_as.count. - */ - VM_WARN_ONCE(data_race(percpu_counter_read(&vm_committed_as) < - -(s64)vm_committed_as_batch * num_online_cpus()), - "memory commitment underflow"); - vm_acct_memory(pages); /* -- 2.7.4