From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755970Ab0ANKWl (ORCPT ); Thu, 14 Jan 2010 05:22:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751622Ab0ANKWk (ORCPT ); Thu, 14 Jan 2010 05:22:40 -0500 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:42435 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932110Ab0ANKWj (ORCPT ); Thu, 14 Jan 2010 05:22:39 -0500 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: Nick Piggin , Jeff Dike , Ingo Molnar , Thomas Gleixner , Andrew Morton , LKML , linux-mm Subject: [PATCH] oom: OOM-Killed process don't invoke pagefault-oom Cc: kosaki.motohiro@jp.fujitsu.com Message-Id: <20100114191940.6749.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.50.07 [ja] Date: Thu, 14 Jan 2010 19:22:34 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Nick, I've found this issue by code review. I'm glad if you review this patch. Thanks. ============================= commit 1c0fe6e3 (invoke oom-killer from page fault) created page fault specific oom handler. But If OOM occur, alloc_pages() in page fault might return NULL. It mean page fault return VM_FAULT_OOM. But OOM Killer itself sholdn't invoke next OOM Kill. it is obviously strange. Plus, process exiting itself makes some free memory. we don't need kill another process. Signed-off-by: KOSAKI Motohiro Cc: Nick Piggin Cc: Jeff Dike Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Andrew Morton --- mm/oom_kill.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 4f167b8..86cecdf 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -596,6 +596,15 @@ void pagefault_out_of_memory(void) { unsigned long freed = 0; + /* + * If the task was received SIGKILL while memory allocation, alloc_pages + * might return NULL and it cause page fault return VM_FAULT_OOM. But + * in such case, the task don't need kill any another task, it need + * just die. + */ + if (fatal_signal_pending(current)) + return; + blocking_notifier_call_chain(&oom_notify_list, 0, &freed); if (freed > 0) /* Got some memory back in the last second. */ -- 1.6.5.2