From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: s2disk hang update Date: Thu, 18 Feb 2010 21:04:49 +0100 Message-ID: <201002182104.49631.rjw__34645.8367458128$1266523511$gmane$org@sisk.pl> References: <9b2b86521001020703v23152d0cy3ba2c08df88c0a79@mail.gmail.com> <201002172058.04043.rjw@sisk.pl> <9b2b86521002180453l176a83dand809dc239c220c08@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <9b2b86521002180453l176a83dand809dc239c220c08@mail.gmail.com> 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: Alan Jenkins Cc: Mel Gorman , linux-kernel , hugh.dickins@tiscali.co.uk, pm list , Kernel Testers List List-Id: linux-pm@vger.kernel.org On Thursday 18 February 2010, Alan Jenkins wrote: > On 2/17/10, Rafael J. Wysocki wrote: > > On Wednesday 17 February 2010, Alan Jenkins wrote: > >> On 2/16/10, Rafael J. Wysocki wrote: > >> > On Tuesday 16 February 2010, Alan Jenkins wrote: > >> >> On 2/16/10, Alan Jenkins wrote: > >> >> > On 2/15/10, Rafael J. Wysocki wrote: > >> >> >> On Tuesday 09 February 2010, Alan Jenkins wrote: > >> >> >>> Perhaps I spoke too soon. I see the same hang if I run too many > >> >> >>> applications. The first hibernation fails with "not enough swap" > >> >> >>> as > >> >> >>> expected, but the second or third attempt hangs (with the same > >> >> >>> backtrace > >> >> >>> as before). > >> >> >>> > >> >> >>> The patch definitely helps though. Without the patch, I see a hang > >> >> >>> the > >> >> >>> first time I try to hibernate with too many applications running. > >> >> >> > >> >> >> Well, I have an idea. > >> >> >> > >> >> >> Can you try to apply the appended patch in addition and see if that > >> >> >> helps? > >> >> >> > >> >> >> Rafael > >> >> > > >> >> > It doesn't seem to help. > >> >> > >> >> To be clear: It doesn't stop the hang when I hibernate with too many > >> >> applications. > >> >> > >> >> It does stop the same hang in a different case though. > >> >> > >> >> 1. boot with init=/bin/bash > >> >> 2. run s2disk > >> >> 3. cancel the s2disk > >> >> 4. repeat steps 2&3 > >> >> > >> >> With the patch, I can run 10s of iterations, with no hang. > >> >> Without the patch, it soon hangs, (in disable_nonboot_cpus(), as > >> >> always). > >> >> > >> >> That's what happens on 2.6.33-rc7. On 2.6.30, there is no problem. > >> >> On 2.6.31 and 2.6.32 I don't get a hang, but dmesg shows an allocation > >> >> failure after a couple of iterations ("kthreadd: page allocation > >> >> failure. order:1, mode:0xd0"). It looks like it might be the same > >> >> stop_machine thread allocation failure that causes the hang. > >> > > >> > Have you tested it alone or on top of the previous one? If you've > >> > tested it > >> > alone, please apply the appended one in addition to it and retest. > >> > > >> > Rafael > >> > >> I did test with both patches applied together - > >> > >> 1. [Update] MM / PM: Force GFP_NOIO during suspend/hibernation and resume > >> 2. "reducing the number of pages that we're going to keep preallocated by > >> 20%" > > > > In that case you can try to reduce the number of preallocated pages even > > more, > > ie. change "/ 5" to "/ 2" (for example) in the second patch. > > It still hangs if I try to hibernate a couple of times with too many > applications. Hmm. I guess I asked that before, but is this a 32-bit or 64-bit system and how much RAM is there in the box? Rafael