Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932999Ab0FCGX6 (ORCPT ); Thu, 3 Jun 2010 02:23:58 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:54511 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932836Ab0FCGXx (ORCPT ); Thu, 3 Jun 2010 02:23:53 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: "Luis Claudio R. Goncalves" , LKML , linux-mm , Oleg Nesterov , David Rientjes , Andrew Morton , KAMEZAWA Hiroyuki , Nick Piggin Subject: [PATCH 07/12] oom: Fix child process iteration properly Cc: kosaki.motohiro@jp.fujitsu.com In-Reply-To: <20100603135106.7247.A69D9226@jp.fujitsu.com> References: <20100603135106.7247.A69D9226@jp.fujitsu.com> Message-Id: <20100603152304.725C.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, 3 Jun 2010 15:23:50 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2735 Lines: 92 Oleg pointed out that current oom child process iterating logic is wrong. > list_for_each_entry(p->children) can only see the tasks forked > by p, it can't see other children forked by its sub-threads. This patch fixes it. Reported-by: Oleg Nesterov Signed-off-by: KOSAKI Motohiro --- mm/oom_kill.c | 35 +++++++++++++++++++++-------------- 1 files changed, 21 insertions(+), 14 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index d4484c5..35a2ecc 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -88,6 +88,7 @@ unsigned long badness(struct task_struct *p, unsigned long uptime) { unsigned long points, cpu_time, run_time; struct task_struct *c; + struct task_struct *t; struct task_struct *child; int oom_adj = p->signal->oom_adj; struct task_cputime task_time; @@ -125,14 +126,17 @@ unsigned long badness(struct task_struct *p, unsigned long uptime) * child is eating the vast majority of memory, adding only half * to the parents will make the child our kill candidate of choice. */ - list_for_each_entry(c, &p->children, sibling) { - child = find_lock_task_mm(c); - if (child) { - if (child->mm != p->mm) - points += child->mm->total_vm/2 + 1; - task_unlock(child); + t = p; + do { + list_for_each_entry(c, &t->children, sibling) { + child = find_lock_task_mm(c); + if (child) { + if (child->mm != p->mm) + points += child->mm->total_vm/2 + 1; + task_unlock(child); + } } - } + } while_each_thread(p, t); /* * CPU time is in tens of seconds and run time is in thousands @@ -432,6 +436,7 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, const char *message) { struct task_struct *c; + struct task_struct *t = p; if (printk_ratelimit()) dump_header(p, gfp_mask, order, mem); @@ -449,14 +454,16 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, message, task_pid_nr(p), p->comm, points); /* Try to kill a child first */ - list_for_each_entry(c, &p->children, sibling) { - if (c->mm == p->mm) - continue; + do { + list_for_each_entry(c, &t->children, sibling) { + if (c->mm == p->mm) + continue; - /* Ok, Kill the child */ - if (!__oom_kill_process(c, mem, 1)) - return 0; - } + /* Ok, Kill the child */ + if (!__oom_kill_process(c, mem, 1)) + return 0; + } + } while_each_thread(p, t); return __oom_kill_process(p, mem, 1); } -- 1.6.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/