From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752925AbaJPVOy (ORCPT ); Thu, 16 Oct 2014 17:14:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51837 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751318AbaJPVOw (ORCPT ); Thu, 16 Oct 2014 17:14:52 -0400 Date: Thu, 16 Oct 2014 23:11:36 +0200 From: Oleg Nesterov To: Cong Wang Cc: Michal Hocko , David Rientjes , "Rafael J. Wysocki" , Tejun Heo , Andrew Morton , LKML Subject: Re: + freezer-check-oom-kill-while-being-frozen.patch added to -mm tree Message-ID: <20141016211136.GA27468@redhat.com> References: <20141016203954.GA26336@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/16, Cong Wang wrote: > > On Thu, Oct 16, 2014 at 1:39 PM, Oleg Nesterov wrote: > >> Fix the issue by checking for TIF_MEMDIE thread flag and get away from the > >> fridge if it is set. oom_scan_process_thread doesn't have to check for > >> the frozen task anymore because do_send_sig_info will wake up the thread > >> and TIF_MEMDIE is already set by that time. > > > > I must have missed something... but __refrigerator() sleeps in > > TASK_UNINTERRUPTIBLE and do_send_sig_info() won't wake it up? > > > > This is exactly what we are trying to fix. Make sure you read the patch > as well before reply? I did read the patch, but I can't understand it. I am sorry about that, and I am asking for your help. I agree that oom_scan_process_thread()->__thaw_task() doesn't really help. But also I can't understand why this patch helps. The changelog says: do_send_sig_info will wake up the thread why? Oleg.