From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935124AbcCPPOy (ORCPT ); Wed, 16 Mar 2016 11:14:54 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:65226 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932331AbcCPPOv (ORCPT ); Wed, 16 Mar 2016 11:14:51 -0400 Subject: Re: [PATCH] mmc: card: don't use PF_MEMALLOC To: Martin Kepplinger , , , References: <1458128635-3539-1-git-send-email-martink@posteo.de> <56E9707D.5070004@fb.com> <56E976A9.40906@posteo.de> CC: , From: Jens Axboe Message-ID: <56E977DB.90302@fb.com> Date: Wed, 16 Mar 2016 08:12:27 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <56E976A9.40906@posteo.de> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.54.13] X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-03-16_04:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/16/2016 08:07 AM, Martin Kepplinger wrote: > Am 2016-03-16 um 15:41 schrieb Jens Axboe: >> On 03/16/2016 04:43 AM, Martin Kepplinger wrote: >>> PF_MEMALLOC is assigned to processes by mm. If drivers prevent memory >>> reclaim and mm is not in control, strange hang-up or OOM Killer >>> invocation >>> could happen. >>> >>> Signed-off-by: Martin Kepplinger >>> --- >>> I use MMC cards with this change perfectly fine. As I understand it, >>> even *if* PF_MEMALLOC has a real reason to be here, I think it should >>> be very well documented. >> >> Did you try swap on mmcblk? >> > > No I haven't even thought about that :) If you know it can be necessary > in that case, it's obviously fine. A comment would still be good though. That's why it is there! So yes, adding a comment to that effect would be a better path forward. -- Jens Axboe