From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with SMTP id C886F6B006A for ; Wed, 20 Jan 2010 19:47:22 -0500 (EST) Received: from m6.gw.fujitsu.co.jp ([10.0.50.76]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o0L0lK9p002100 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Thu, 21 Jan 2010 09:47:20 +0900 Received: from smail (m6 [127.0.0.1]) by outgoing.m6.gw.fujitsu.co.jp (Postfix) with ESMTP id E1D0E45DE4E for ; Thu, 21 Jan 2010 09:47:19 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (s6.gw.fujitsu.co.jp [10.0.50.96]) by m6.gw.fujitsu.co.jp (Postfix) with ESMTP id C491A45DD6D for ; Thu, 21 Jan 2010 09:47:19 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id EA689E08002 for ; Thu, 21 Jan 2010 09:47:18 +0900 (JST) Received: from ml13.s.css.fujitsu.com (ml13.s.css.fujitsu.com [10.249.87.103]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id 872F51DB8040 for ; Thu, 21 Jan 2010 09:47:15 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [RFC][PATCH] PM: Force GFP_NOIO during suspend/resume (was: Re: [linux-pm] Memory allocations in .suspend became very unreliable) In-Reply-To: <201001202221.34804.rjw@sisk.pl> References: <20100120085053.405A.A69D9226@jp.fujitsu.com> <201001202221.34804.rjw@sisk.pl> Message-Id: <20100121091023.3775.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Date: Thu, 21 Jan 2010 09:47:14 +0900 (JST) Sender: owner-linux-mm@kvack.org To: "Rafael J. Wysocki" Cc: kosaki.motohiro@jp.fujitsu.com, Benjamin Herrenschmidt , Maxim Levitsky , linux-pm@lists.linux-foundation.org, LKML , linux-mm , Andrew Morton List-ID: > > Hi Rafael, > > > > Do you mean this is the unrelated issue of nVidia bug? > > The nvidia driver _is_ buggy, but Maxim said he couldn't reproduce the > problem if all the allocations made by the nvidia driver during suspend > were changed to GFP_ATOMIC. > > > Probably I haven't catch your point. I don't find Maxim's original bug > > report. Can we share the test-case and your analysis detail? > > The Maxim's original report is here: > https://lists.linux-foundation.org/pipermail/linux-pm/2010-January/023982.html > > and the message I'm referring to is at: > https://lists.linux-foundation.org/pipermail/linux-pm/2010-January/023990.html Hmmm... Usually, Increasing I/O isn't caused MM change. either subsystem change memory alloc/free pattern and another subsystem receive such effect ;) I don't think this message indicate MM fault. And, 2.6.33 MM change is not much. if the fault is in MM change (note: my guess is no), The most doubtful patch is my "killing shrink_all_zones" patch. If old shrink_all_zones reclaimed memory much rather than required. The patch fixed it. IOW, the patch can reduce available free memory to be used buggy .suspend of the driver. but I don't think it is MM fault. As I said, drivers can't use memory freely as their demand in suspend method. It's obvious. They should stop such unrealistic assumption. but How should we fix this? - Gurantee suspend I/O device at last? - Make much much free memory before calling .suspend method? even though typical drivers don't need. - Ask all drivers how much they require memory before starting suspend and Make enough free memory at first? - Or, do we have an alternative way? Probably we have multiple option. but I don't think GFP_NOIO is good option. It assume the system have lots non-dirty cache memory and it isn't guranteed. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org