From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752549Ab0KZXLO (ORCPT ); Fri, 26 Nov 2010 18:11:14 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:33365 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751949Ab0KZXLN (ORCPT ); Fri, 26 Nov 2010 18:11:13 -0500 From: "Rafael J. Wysocki" To: Ondrej Zary Subject: Re: 2.6.35.5: hibernation broken... AGAIN Date: Sat, 27 Nov 2010 00:10:04 +0100 User-Agent: KMail/1.13.5 (Linux/2.6.37-rc3+; KDE/4.4.4; x86_64; ; ) Cc: Hugh Dickins , Andrew Morton , KAMEZAWA Hiroyuki , KOSAKI Motohiro , Kernel development list , Balbir Singh References: <201011171139.33398.linux@rainbow-software.org> <201011261243.15091.linux@rainbow-software.org> In-Reply-To: <201011261243.15091.linux@rainbow-software.org> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201011270010.04323.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday, November 26, 2010, Ondrej Zary wrote: > On Thursday 18 November 2010, Hugh Dickins wrote: > > On Wed, 17 Nov 2010, Ondrej Zary wrote: > > > On Wednesday 17 November 2010 22:12:01 Rafael J. Wysocki wrote: > > > > On Wednesday, November 17, 2010, Andrew Morton wrote: > > > > > On Wed, 17 Nov 2010 21:53:52 +0100 > > > > > > > > > > "Rafael J. Wysocki" wrote: > > > > > > On Wednesday, November 17, 2010, Ondrej Zary wrote: > > > > > > > Hello, > > > > > > > the nasty memory-corrupting hibernation bug > > > > > > > https://bugzilla.kernel.org/show_bug.cgi?id=15753 is back since > > > > > > > 2.6.35.5. 2.6.35.4 works fine, 2.6.35.5 crashes after two days. > > > > That's distressing, for both and all of us: I'm sorry. > > > > > > > > > It seems to be caused by > > > > > > > b77c254d8d66e5e9aa81239fedba9f3d568097d9. > > > > > > > > > > commit b77c254d8d66e5e9aa81239fedba9f3d568097d9 > > > > > Author: Hugh Dickins > > > > > Date: Thu Sep 9 16:38:09 2010 -0700 > > > > > > > > > > swap: prevent reuse during hibernation > > > > Embarrassing: I suspect that I've been confused, not for the first > > time, by the fork-like nature of hibernation and its images. > > I wonder if this patch below fixes it, Ondrej? > > > > (And is it kernel swsusp or user swsusp that you're using? May not > > matter at all, but will help us to think more clearly about it, > > if the corruption remains after this patch.) > > > > Rafael, do you agree that this patch was actually required even for > > your original commit 452aa6999e6703ffbddd7f6ea124d3968915f3e3 > > mm/pm: force GFP_NOIO during suspend/hibernation and resume? > > > > Or am I still just as confused? Or if not, are there more forking > > places which require a similar patch? > > > > Not signing it off yet, > > Hugh > > Could you please do that? The patch fixes the problem. Can you check if the problem is also fixed by the patch below, please? Rafael --- kernel/power/hibernate.c | 36 ++++++++++++++++++++++++++---------- kernel/power/power.h | 1 + kernel/power/user.c | 1 + 3 files changed, 28 insertions(+), 10 deletions(-) Index: linux-2.6/kernel/power/hibernate.c =================================================================== --- linux-2.6.orig/kernel/power/hibernate.c +++ linux-2.6/kernel/power/hibernate.c @@ -29,6 +29,21 @@ #include "power.h" +static gfp_t saved_gfp_mask; + +static void hibernate_restrict_gfp_mask(void) +{ + saved_gfp_mask = clear_gfp_allowed_mask(GFP_IOFS); +} + +void hibernate_restore_gfp_mask(void) +{ + if (saved_gfp_mask) { + set_gfp_allowed_mask(saved_gfp_mask); + saved_gfp_mask = 0; + } +} + static int nocompress = 0; static int noresume = 0; static char resume_file[256] = CONFIG_PM_STD_PARTITION; @@ -327,7 +342,6 @@ static int create_image(int platform_mod int hibernation_snapshot(int platform_mode) { int error; - gfp_t saved_mask; error = platform_begin(platform_mode); if (error) @@ -339,7 +353,7 @@ int hibernation_snapshot(int platform_mo goto Close; suspend_console(); - saved_mask = clear_gfp_allowed_mask(GFP_IOFS); + hibernate_restrict_gfp_mask(); error = dpm_suspend_start(PMSG_FREEZE); if (error) goto Recover_platform; @@ -348,7 +362,10 @@ int hibernation_snapshot(int platform_mo goto Recover_platform; error = create_image(platform_mode); - /* Control returns here after successful restore */ + /* + * Control returns here (1) after the image has been created or the + * image creation has failed and (2) after a successful restore. + */ Resume_devices: /* We may need to release the preallocated image pages here. */ @@ -357,7 +374,10 @@ int hibernation_snapshot(int platform_mo dpm_resume_end(in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE); - set_gfp_allowed_mask(saved_mask); + + if (error || !in_suspend) + hibernate_restore_gfp_mask(); + resume_console(); Close: platform_end(platform_mode); @@ -452,17 +472,16 @@ static int resume_target_kernel(bool pla int hibernation_restore(int platform_mode) { int error; - gfp_t saved_mask; pm_prepare_console(); suspend_console(); - saved_mask = clear_gfp_allowed_mask(GFP_IOFS); + hibernate_restrict_gfp_mask(); error = dpm_suspend_start(PMSG_QUIESCE); if (!error) { error = resume_target_kernel(platform_mode); dpm_resume_end(PMSG_RECOVER); } - set_gfp_allowed_mask(saved_mask); + hibernate_restore_gfp_mask(); resume_console(); pm_restore_console(); return error; @@ -476,7 +495,6 @@ int hibernation_restore(int platform_mod int hibernation_platform_enter(void) { int error; - gfp_t saved_mask; if (!hibernation_ops) return -ENOSYS; @@ -492,7 +510,6 @@ int hibernation_platform_enter(void) entering_platform_hibernation = true; suspend_console(); - saved_mask = clear_gfp_allowed_mask(GFP_IOFS); error = dpm_suspend_start(PMSG_HIBERNATE); if (error) { if (hibernation_ops->recover) @@ -536,7 +553,6 @@ int hibernation_platform_enter(void) Resume_devices: entering_platform_hibernation = false; dpm_resume_end(PMSG_RESTORE); - set_gfp_allowed_mask(saved_mask); resume_console(); Close: Index: linux-2.6/kernel/power/power.h =================================================================== --- linux-2.6.orig/kernel/power/power.h +++ linux-2.6/kernel/power/power.h @@ -52,6 +52,7 @@ static inline char *check_image_kernel(s extern int hibernation_snapshot(int platform_mode); extern int hibernation_restore(int platform_mode); extern int hibernation_platform_enter(void); +extern void hibernate_restore_gfp_mask(void); #else /* !CONFIG_HIBERNATION */ Index: linux-2.6/kernel/power/user.c =================================================================== --- linux-2.6.orig/kernel/power/user.c +++ linux-2.6/kernel/power/user.c @@ -263,6 +263,7 @@ static long snapshot_ioctl(struct file * case SNAPSHOT_UNFREEZE: if (!data->frozen || data->ready) break; + hibernate_restore_gfp_mask(); thaw_processes(); usermodehelper_enable(); data->frozen = 0;