From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753395Ab0LAAjy (ORCPT ); Tue, 30 Nov 2010 19:39:54 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:43342 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752918Ab0LAAjx (ORCPT ); Tue, 30 Nov 2010 19:39:53 -0500 From: "Rafael J. Wysocki" To: Hugh Dickins Subject: Re: 2.6.35.5: hibernation broken... AGAIN Date: Wed, 1 Dec 2010 01:38:53 +0100 User-Agent: KMail/1.13.5 (Linux/2.6.37-rc4+; KDE/4.4.4; x86_64; ; ) Cc: Ondrej Zary , Andrew Morton , KAMEZAWA Hiroyuki , KOSAKI Motohiro , Kernel development list , Balbir Singh References: <201011171139.33398.linux@rainbow-software.org> <201012010007.44553.rjw@sisk.pl> In-Reply-To: <201012010007.44553.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201012010138.53575.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday, December 01, 2010, Rafael J. Wysocki wrote: > On Tuesday, November 30, 2010, Hugh Dickins wrote: > > On Sat, 27 Nov 2010, Rafael J. Wysocki wrote: > > > On Saturday, November 27, 2010, Ondrej Zary wrote: ... > > > > Trivial point, I suppose, but it bothers me that PM is accumulating > > wrappers around wrappers around gfp_allowed_mask. Looks like > > clear_gfp_allowed_mask and set_gfp_allowed_mask (oddly asymmetrical) > > were not really what we need. How about scrapping them, and putting > > pm_restrict_gfp_mask() and pm_restore_gfp_mask() into page_alloc.c? > > Sure, that sounds like a good idea indeed. Below is an updated patch in which I tried to address your comments. I didn't find it very useful to couple pm_restore_gfp_mask() with the thawing of tasks, but nevertheless I think all of the spots where it's needed are covered now. The patch has only been compile-tested for now, so caveat emptor. Thanks, Rafael --- include/linux/gfp.h | 4 ++-- kernel/power/hibernate.c | 22 ++++++++++++---------- kernel/power/suspend.c | 5 ++--- kernel/power/user.c | 2 ++ mm/page_alloc.c | 18 +++++++++++------- 5 files changed, 29 insertions(+), 22 deletions(-) Index: linux-2.6/kernel/power/hibernate.c =================================================================== --- linux-2.6.orig/kernel/power/hibernate.c +++ linux-2.6/kernel/power/hibernate.c @@ -327,7 +327,6 @@ 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 +338,7 @@ int hibernation_snapshot(int platform_mo goto Close; suspend_console(); - saved_mask = clear_gfp_allowed_mask(GFP_IOFS); + pm_restrict_gfp_mask(); error = dpm_suspend_start(PMSG_FREEZE); if (error) goto Recover_platform; @@ -348,7 +347,10 @@ 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 +359,10 @@ 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) + pm_restore_gfp_mask(); + resume_console(); Close: platform_end(platform_mode); @@ -452,17 +457,16 @@ 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); + pm_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); + pm_restore_gfp_mask(); resume_console(); pm_restore_console(); return error; @@ -476,7 +480,6 @@ int hibernation_restore(int platform_mod int hibernation_platform_enter(void) { int error; - gfp_t saved_mask; if (!hibernation_ops) return -ENOSYS; @@ -492,7 +495,6 @@ 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 +538,6 @@ 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: @@ -647,6 +648,7 @@ int hibernate(void) if (!error) power_down(); in_suspend = 0; + pm_restore_gfp_mask(); } else { pr_debug("PM: Image restored successfully.\n"); } 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; + pm_restore_gfp_mask(); thaw_processes(); usermodehelper_enable(); data->frozen = 0; @@ -275,6 +276,7 @@ static long snapshot_ioctl(struct file * error = -EPERM; break; } + pm_restore_gfp_mask(); error = hibernation_snapshot(data->platform_support); if (!error) error = put_user(in_suspend, (int __user *)arg); Index: linux-2.6/mm/page_alloc.c =================================================================== --- linux-2.6.orig/mm/page_alloc.c +++ linux-2.6/mm/page_alloc.c @@ -104,19 +104,23 @@ gfp_t gfp_allowed_mask __read_mostly = G * only be modified with pm_mutex held, unless the suspend/hibernate code is * guaranteed not to run in parallel with that modification). */ -void set_gfp_allowed_mask(gfp_t mask) + +static gfp_t saved_gfp_mask; + +void pm_restore_gfp_mask(void) { WARN_ON(!mutex_is_locked(&pm_mutex)); - gfp_allowed_mask = mask; + if (saved_gfp_mask) { + gfp_allowed_mask = saved_gfp_mask; + saved_gfp_mask = 0; + } } -gfp_t clear_gfp_allowed_mask(gfp_t mask) +void pm_restrict_gfp_mask(void) { - gfp_t ret = gfp_allowed_mask; - WARN_ON(!mutex_is_locked(&pm_mutex)); - gfp_allowed_mask &= ~mask; - return ret; + saved_gfp_mask = gfp_allowed_mask; + gfp_allowed_mask &= ~GFP_IOFS; } #endif /* CONFIG_PM_SLEEP */ Index: linux-2.6/include/linux/gfp.h =================================================================== --- linux-2.6.orig/include/linux/gfp.h +++ linux-2.6/include/linux/gfp.h @@ -360,7 +360,7 @@ void drain_local_pages(void *dummy); extern gfp_t gfp_allowed_mask; -extern void set_gfp_allowed_mask(gfp_t mask); -extern gfp_t clear_gfp_allowed_mask(gfp_t mask); +extern void pm_restrict_gfp_mask(void); +extern void pm_restore_gfp_mask(void); #endif /* __LINUX_GFP_H */ Index: linux-2.6/kernel/power/suspend.c =================================================================== --- linux-2.6.orig/kernel/power/suspend.c +++ linux-2.6/kernel/power/suspend.c @@ -197,7 +197,6 @@ static int suspend_enter(suspend_state_t int suspend_devices_and_enter(suspend_state_t state) { int error; - gfp_t saved_mask; if (!suspend_ops) return -ENOSYS; @@ -208,7 +207,7 @@ int suspend_devices_and_enter(suspend_st goto Close; } suspend_console(); - saved_mask = clear_gfp_allowed_mask(GFP_IOFS); + pm_restrict_gfp_mask(); suspend_test_start(); error = dpm_suspend_start(PMSG_SUSPEND); if (error) { @@ -225,7 +224,7 @@ int suspend_devices_and_enter(suspend_st suspend_test_start(); dpm_resume_end(PMSG_RESUME); suspend_test_finish("resume devices"); - set_gfp_allowed_mask(saved_mask); + pm_restore_gfp_mask(); resume_console(); Close: if (suspend_ops->end)