From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: [PATCH 0/3] PM: Drop shrink_all_memory (was: Re: [Bug #13058] First hibernation attempt fails) Date: Sat, 2 May 2009 00:26:18 +0200 Message-ID: <200905020026.19027.rjw__39843.4355309748$1241218763$gmane$org@sisk.pl> References: <200904222211.18221.rjw@sisk.pl> <20090422131943.69288af3.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20090422131943.69288af3.akpm@linux-foundation.org> Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org To: Andrew Morton Cc: linux-kernel@vger.kernel.org, alan-jenkins@tuffmail.co.uk, jens.axboe@oracle.com, pm list , kernel-testers@vger.kernel.org, torvalds@linux-foundation.org List-Id: linux-pm@vger.kernel.org On Wednesday 22 April 2009, Andrew Morton wrote: > On Wed, 22 Apr 2009 22:11:17 +0200 > "Rafael J. Wysocki" wrote: > > > On Wednesday 22 April 2009, Pavel Machek wrote: > > > Hi! > > > > > > > Of course, this will protect the calling task from getting oom-killed. > > > > But it doesn't protect other tasks from getting oom-killed due to the > > > > activity of _this_ task. > > > > > > > > But I think that problem already exists, and that this proposal doesn't > > > > worsen anything, yes? > > > > > > > > Or is it the case that all other tasks are safely stuck in the freezer > > > > at this time, so they won't be allocating any memory anyway? > > > > > > That is the idea, yes. ... but we now have more threads that are not > > > freezable... so they may allocate the memory. > > > > > > Is it non-feasible to free memory without really going and allocating > > > everything? > > > > The question is whether there is a point. In principle we can just go and > > allocate as much as we need upfront. It shouldn't change anything, because > > we resume and suspend devices after creating the image anyway. > > > > I think we could try to disable the OOM killer before suspend and just > > allocate the memory for the image right before devices are suspended for the > > first time. > > > > It would be nice to do. > > shrink_all_memory() is simply trying to do something which page reclaim > doesn't expect to do (free memory when there's already lots of memory > free). Consequently it doesn't do it very well, and there's a good > risk that changes to core reclaim will accidentally break > shrink_all_memory(). OK, a patchset follows: [1/3] - disable the OOM killer during system-wide power transitions (should be done anyway IMO) [2/3] - move swsusp_shrink_memory() to kernel/power/snapshot.c so that the next patch is easier to read [3/3] - drop shrink_all_memory() Please have a look and tell me what you think. Thanks, Rafael