From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965084AbXDMWpL (ORCPT ); Fri, 13 Apr 2007 18:45:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965277AbXDMWpL (ORCPT ); Fri, 13 Apr 2007 18:45:11 -0400 Received: from nigel.suspend2.net ([203.171.70.205]:36216 "EHLO nigel.suspend2.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965084AbXDMWpJ (ORCPT ); Fri, 13 Apr 2007 18:45:09 -0400 Subject: Re: [RFD] swsusp problem: Drivers allocate much memory during suspend (was: Re: 2.6.21-rc5: swsusp: Not enough free memory) From: Nigel Cunningham To: Pavel Machek Cc: "Rafael J. Wysocki" , Jiri Slaby , Linux kernel mailing list , linux-pm@lists.osdl.org In-Reply-To: <20070413224053.GT28264@elf.ucw.cz> References: <460B6E4B.3060004@gmail.com> <200704132241.52725.rjw@sisk.pl> <20070413221016.GQ28264@elf.ucw.cz> <200704140035.36355.rjw@sisk.pl> <20070413224053.GT28264@elf.ucw.cz> Content-Type: text/plain Date: Sat, 14 Apr 2007 08:45:06 +1000 Message-Id: <1176504306.7112.206.camel@nigel.suspend2.net> Mime-Version: 1.0 X-Mailer: Evolution 2.10.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi. On Sat, 2007-04-14 at 00:40 +0200, Pavel Machek wrote: > Hi! > > > > > > > Well, it looks like someone allocated about 6000 pages after we had freed > > > > > > enough memory for suspending. > > > > > > > > > > We have a tunable allowance in Suspend2 for this, because fglrx > > > > > allocates a lot of pages in its suspend routine if DRI is enabled. I > > > > > think some other drivers do too, but fglrx is the main one I know. > > > > > > > > I wasn't aware of that, thanks for the information. > > > > > > > > I think this means we'll probably need to add a tunable, similar to image_size, > > > > that will allow the users to specify how much spare memory they want to reserve > > > > for suspending (instead of the constant PAGES_FOR_IO). IMO we can call it > > > > 'spare_memory'. > > > > > > Just increase PAGES_FOR_IO. This should not be tunable. > > > > Well, I'm not sure. First, we don't really know what the value of it should be > > and this alone is a good enough reason for making it tunable, IMHO. Second, I > > think different systems may need different PAGES_FOR_IO and taking just the > > maximum (even if we learn how much that actually is) seems to be wasteful in > > Well, it is wasteful as in "we save slightly smaller image than we > could". That's okay with me. No. If the driver can't allocate the memory, your call to device_suspend will fail. This isn't about image size but about success or failure to hibernate. Nigel