* [PATCH -mm 0/3] Suspend notifiers
@ 2007-04-22 18:10 Rafael J. Wysocki
2007-04-22 18:12 ` [PATCH -mm 1/3] swsusp: Fix snapshot_release Rafael J. Wysocki
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Rafael J. Wysocki @ 2007-04-22 18:10 UTC (permalink / raw)
To: Andrew Morton; +Cc: LKML, Nigel Cunningham, Pavel Machek
Hi,
The last two patches from this series are intended to address the problem that
some drivers allocate a lot of memory in their .suspend() routines causing
swsusp to fail (and generally may want to do some things that shouldn't be
done in .suspend()/.resume()).
The first one is a fix.
Greetings,
Rafael
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH -mm 1/3] swsusp: Fix snapshot_release 2007-04-22 18:10 [PATCH -mm 0/3] Suspend notifiers Rafael J. Wysocki @ 2007-04-22 18:12 ` Rafael J. Wysocki 2007-04-22 18:14 ` [PATCH -mm 2/3] swsusp: Free more memory Rafael J. Wysocki 2007-04-22 18:48 ` [PATCH -mm 3/3] PM: Introduce suspend notifiers (rev. 2) Rafael J. Wysocki 2 siblings, 0 replies; 6+ messages in thread From: Rafael J. Wysocki @ 2007-04-22 18:12 UTC (permalink / raw) To: Andrew Morton; +Cc: LKML, Nigel Cunningham, Pavel Machek From: Rafael J. Wysocki <rjw@sisk.pl> Remove the leftover enable_nonboot_cpus() from snapshot_release(). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> --- kernel/power/user.c | 1 - 1 file changed, 1 deletion(-) Index: linux-2.6.21-rc6-mm1/kernel/power/user.c =================================================================== --- linux-2.6.21-rc6-mm1.orig/kernel/power/user.c 2007-04-22 19:55:59.000000000 +0200 +++ linux-2.6.21-rc6-mm1/kernel/power/user.c 2007-04-22 19:56:52.000000000 +0200 @@ -86,7 +86,6 @@ static int snapshot_release(struct inode if (data->frozen) { mutex_lock(&pm_mutex); thaw_processes(); - enable_nonboot_cpus(); mutex_unlock(&pm_mutex); } atomic_inc(&snapshot_device_available); ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH -mm 2/3] swsusp: Free more memory 2007-04-22 18:10 [PATCH -mm 0/3] Suspend notifiers Rafael J. Wysocki 2007-04-22 18:12 ` [PATCH -mm 1/3] swsusp: Fix snapshot_release Rafael J. Wysocki @ 2007-04-22 18:14 ` Rafael J. Wysocki 2007-04-22 18:48 ` [PATCH -mm 3/3] PM: Introduce suspend notifiers (rev. 2) Rafael J. Wysocki 2 siblings, 0 replies; 6+ messages in thread From: Rafael J. Wysocki @ 2007-04-22 18:14 UTC (permalink / raw) To: Andrew Morton; +Cc: LKML, Nigel Cunningham, Pavel Machek From: Rafael J. Wysocki <rjw@sisk.pl> Move the definition of PAGES_FOR_IO to kernel/power/power.h and introduce SPARE_PAGES representing the number of pages that should be freed by the swsusp's memory shrinker in addition to PAGES_FOR_IO so that device drivers can allocate some memory (up to 1 MB total) in their .suspend() routines without causing the suspend to fail. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> --- include/linux/suspend.h | 6 ------ kernel/power/power.h | 12 +++++++++++- kernel/power/swsusp.c | 2 +- 3 files changed, 12 insertions(+), 8 deletions(-) Index: linux-2.6.21-rc6-mm1/include/linux/suspend.h =================================================================== --- linux-2.6.21-rc6-mm1.orig/include/linux/suspend.h 2007-04-21 23:24:28.000000000 +0200 +++ linux-2.6.21-rc6-mm1/include/linux/suspend.h 2007-04-21 23:24:44.000000000 +0200 @@ -60,10 +60,4 @@ struct saved_context; void __save_processor_state(struct saved_context *ctxt); void __restore_processor_state(struct saved_context *ctxt); -/* - * XXX: We try to keep some more pages free so that I/O operations succeed - * without paging. Might this be more? - */ -#define PAGES_FOR_IO 1024 - #endif /* _LINUX_SWSUSP_H */ Index: linux-2.6.21-rc6-mm1/kernel/power/power.h =================================================================== --- linux-2.6.21-rc6-mm1.orig/kernel/power/power.h 2007-04-21 23:24:28.000000000 +0200 +++ linux-2.6.21-rc6-mm1/kernel/power/power.h 2007-04-21 23:24:44.000000000 +0200 @@ -14,8 +14,18 @@ struct swsusp_info { #ifdef CONFIG_SOFTWARE_SUSPEND -extern int pm_suspend_disk(void); +/* + * Keep some memory free so that I/O operations can succeed without paging + * [Might this be more than 4 MB?] + */ +#define PAGES_FOR_IO ((4096 * 1024) >> PAGE_SHIFT) +/* + * Keep 1 MB of memory free so that device drivers can allocate some pages in + * their .suspend() routines without breaking the suspend to disk. + */ +#define SPARE_PAGES ((1024 * 1024) >> PAGE_SHIFT) +extern int pm_suspend_disk(void); #else static inline int pm_suspend_disk(void) { Index: linux-2.6.21-rc6-mm1/kernel/power/swsusp.c =================================================================== --- linux-2.6.21-rc6-mm1.orig/kernel/power/swsusp.c 2007-04-21 22:37:50.000000000 +0200 +++ linux-2.6.21-rc6-mm1/kernel/power/swsusp.c 2007-04-21 23:24:44.000000000 +0200 @@ -233,7 +233,7 @@ int swsusp_shrink_memory(void) long size, highmem_size; highmem_size = count_highmem_pages(); - size = count_data_pages() + PAGES_FOR_IO; + size = count_data_pages() + PAGES_FOR_IO + SPARE_PAGES; tmp = size; size += highmem_size; for_each_zone (zone) ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH -mm 3/3] PM: Introduce suspend notifiers (rev. 2) 2007-04-22 18:10 [PATCH -mm 0/3] Suspend notifiers Rafael J. Wysocki 2007-04-22 18:12 ` [PATCH -mm 1/3] swsusp: Fix snapshot_release Rafael J. Wysocki 2007-04-22 18:14 ` [PATCH -mm 2/3] swsusp: Free more memory Rafael J. Wysocki @ 2007-04-22 18:48 ` Rafael J. Wysocki 2007-04-24 10:28 ` Andrew Morton 2 siblings, 1 reply; 6+ messages in thread From: Rafael J. Wysocki @ 2007-04-22 18:48 UTC (permalink / raw) To: Andrew Morton; +Cc: LKML, Nigel Cunningham, Pavel Machek From: Rafael J. Wysocki <rjw@sisk.pl> Make it possible to register suspend notifiers so that subsystems can perform suspend-related operations that should not be carried out by device drivers' .suspend() and .resume() routines. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> --- Documentation/power/suspend-notifiers.txt | 48 ++++++++++++++++++++++++++++ include/linux/notifier.h | 6 +++ include/linux/suspend.h | 27 +++++++++++++-- kernel/power/Makefile | 2 - kernel/power/disk.c | 23 ++++++++++++- kernel/power/main.c | 16 ++++++++- kernel/power/notify.c | 51 ++++++++++++++++++++++++++++++ kernel/power/power.h | 3 + kernel/power/user.c | 45 ++++++++++++++++++++------ 9 files changed, 203 insertions(+), 18 deletions(-) Index: linux-2.6.21-rc6-mm1/kernel/power/notify.c =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux-2.6.21-rc6-mm1/kernel/power/notify.c 2007-04-22 19:57:08.000000000 +0200 @@ -0,0 +1,51 @@ +/* + * linux/kernel/power/notify.c + * + * This file contains functions used for registering and calling suspend + * notifiers that can be used by subsystems for carrying out some special + * suspend-related operations. + * + * Copyright (C) 2007 Rafael J. Wysocki <rjw@sisk.pl> + * + * This file is released under the GPLv2. + * + */ + +#include <linux/smp.h> +#include <linux/notifier.h> +#include <linux/module.h> +#include <linux/suspend.h> + +static DEFINE_MUTEX(suspend_notifier_lock); + +static RAW_NOTIFIER_HEAD(suspend_chain); + +int register_suspend_notifier(struct notifier_block *nb) +{ + int ret; + mutex_lock(&suspend_notifier_lock); + ret = raw_notifier_chain_register(&suspend_chain, nb); + mutex_unlock(&suspend_notifier_lock); + return ret; +} +EXPORT_SYMBOL(register_suspend_notifier); + +void unregister_suspend_notifier(struct notifier_block *nb) +{ + mutex_lock(&suspend_notifier_lock); + raw_notifier_chain_unregister(&suspend_chain, nb); + mutex_unlock(&suspend_notifier_lock); +} +EXPORT_SYMBOL(unregister_suspend_notifier); + +int suspend_notifier_call_chain(unsigned long val) +{ + int error = 0; + + mutex_lock(&suspend_notifier_lock); + if (raw_notifier_call_chain(&suspend_chain, val, NULL) == NOTIFY_BAD) + error = -EINVAL; + + mutex_unlock(&suspend_notifier_lock); + return error; +} Index: linux-2.6.21-rc6-mm1/include/linux/suspend.h =================================================================== --- linux-2.6.21-rc6-mm1.orig/include/linux/suspend.h 2007-04-22 19:57:08.000000000 +0200 +++ linux-2.6.21-rc6-mm1/include/linux/suspend.h 2007-04-22 19:57:08.000000000 +0200 @@ -24,15 +24,16 @@ struct pbe { extern void drain_local_pages(void); extern void mark_free_pages(struct zone *zone); -#if defined(CONFIG_PM) && defined(CONFIG_VT) && defined(CONFIG_VT_CONSOLE) +#ifdef CONFIG_PM +#if defined(CONFIG_VT) && defined(CONFIG_VT_CONSOLE) extern int pm_prepare_console(void); extern void pm_restore_console(void); #else static inline int pm_prepare_console(void) { return 0; } static inline void pm_restore_console(void) {} -#endif +#endif /* defined(CONFIG_VT) && defined(CONFIG_VT_CONSOLE) */ -#if defined(CONFIG_PM) && defined(CONFIG_SOFTWARE_SUSPEND) +#ifdef CONFIG_SOFTWARE_SUSPEND /* kernel/power/swsusp.c */ extern int software_suspend(void); /* kernel/power/snapshot.c */ @@ -52,7 +53,7 @@ static inline void register_nosave_regio static inline int swsusp_page_is_forbidden(struct page *p) { return 0; } static inline void swsusp_set_page_free(struct page *p) {} static inline void swsusp_unset_page_free(struct page *p) {} -#endif /* defined(CONFIG_PM) && defined(CONFIG_SOFTWARE_SUSPEND) */ +#endif /* CONFIG_SOFTWARE_SUSPEND */ void save_processor_state(void); void restore_processor_state(void); @@ -60,4 +61,22 @@ struct saved_context; void __save_processor_state(struct saved_context *ctxt); void __restore_processor_state(struct saved_context *ctxt); +int register_suspend_notifier(struct notifier_block *nb); +void unregister_suspend_notifier(struct notifier_block *nb); + +#define suspend_notifier(fn, pri) { \ + static struct notifier_block fn##_nb = \ + { .notifier_call = fn, .priority = pri }; \ + register_suspend_notifier(&fn##_nb); \ +} +#else /* CONFIG_PM */ +static inline int register_suspend_notifier(struct notifier_block *nb) { + return 0; +} +static inline void unregister_suspend_notifier(struct notifier_block *nb) { +} + +#define suspend_notifier(fn, pri) do { (void)(fn); } while (0) +#endif + #endif /* _LINUX_SWSUSP_H */ Index: linux-2.6.21-rc6-mm1/kernel/power/Makefile =================================================================== --- linux-2.6.21-rc6-mm1.orig/kernel/power/Makefile 2007-04-22 19:55:59.000000000 +0200 +++ linux-2.6.21-rc6-mm1/kernel/power/Makefile 2007-04-22 19:57:08.000000000 +0200 @@ -3,7 +3,7 @@ ifeq ($(CONFIG_PM_DEBUG),y) EXTRA_CFLAGS += -DDEBUG endif -obj-y := main.o process.o console.o +obj-y := main.o process.o console.o notify.o obj-$(CONFIG_PM_LEGACY) += pm.o obj-$(CONFIG_SOFTWARE_SUSPEND) += swsusp.o disk.o snapshot.o swap.o user.o Index: linux-2.6.21-rc6-mm1/kernel/power/power.h =================================================================== --- linux-2.6.21-rc6-mm1.orig/kernel/power/power.h 2007-04-22 19:57:08.000000000 +0200 +++ linux-2.6.21-rc6-mm1/kernel/power/power.h 2007-04-22 19:57:08.000000000 +0200 @@ -170,3 +170,6 @@ extern int suspend_enter(suspend_state_t struct timeval; extern void swsusp_show_speed(struct timeval *, struct timeval *, unsigned int, char *); + +/* kernel/power/notify.c */ +extern int suspend_notifier_call_chain(unsigned long val); Index: linux-2.6.21-rc6-mm1/include/linux/notifier.h =================================================================== --- linux-2.6.21-rc6-mm1.orig/include/linux/notifier.h 2007-04-22 19:55:59.000000000 +0200 +++ linux-2.6.21-rc6-mm1/include/linux/notifier.h 2007-04-22 19:57:08.000000000 +0200 @@ -209,5 +209,11 @@ extern int __srcu_notifier_call_chain(st #define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN) #define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN) +#define SUSPEND_PREPARE 0x0002 /* Going to freeze tasks */ +#define SUSPEND_ENTER_PREPARE 0x0003 /* Tasks are frozen, we are suspending */ +#define SUSPEND_THAW_PREPARE 0x0004 /* Going to thaw frozen tasks */ +#define SUSPEND_FINISHED 0x0005 /* Tasks have been thawed */ +#define SUSPEND_RESTORE_PREPARE 0x0006 /* STD restore is going to happen */ + #endif /* __KERNEL__ */ #endif /* _LINUX_NOTIFIER_H */ Index: linux-2.6.21-rc6-mm1/kernel/power/disk.c =================================================================== --- linux-2.6.21-rc6-mm1.orig/kernel/power/disk.c 2007-04-22 19:55:59.000000000 +0200 +++ linux-2.6.21-rc6-mm1/kernel/power/disk.c 2007-04-22 20:37:08.000000000 +0200 @@ -139,10 +139,18 @@ int pm_suspend_disk(void) if (error) goto Exit; + error = suspend_notifier_call_chain(SUSPEND_PREPARE); + if (error) + goto Finish; + error = prepare_processes(); if (error) goto Finish; + error = suspend_notifier_call_chain(SUSPEND_ENTER_PREPARE); + if (error) + goto Thaw; + if (pm_disk_mode == PM_DISK_TESTPROC) { printk("swsusp debug: Waiting for 5 seconds.\n"); mdelay(5000); @@ -205,8 +213,10 @@ int pm_suspend_disk(void) device_resume(); resume_console(); Thaw: + suspend_notifier_call_chain(SUSPEND_THAW_PREPARE); unprepare_processes(); Finish: + suspend_notifier_call_chain(SUSPEND_FINISHED); free_basic_memory_bitmaps(); Exit: atomic_inc(&snapshot_device_available); @@ -267,6 +277,10 @@ static int software_resume(void) if (error) goto Finish; + error = suspend_notifier_call_chain(SUSPEND_PREPARE); + if (error) + goto Done; + pr_debug("PM: Preparing processes for restore.\n"); error = prepare_processes(); if (error) { @@ -279,9 +293,13 @@ static int software_resume(void) error = swsusp_read(); if (error) { swsusp_free(); - goto Thaw; + goto Unprepare; } + error = suspend_notifier_call_chain(SUSPEND_RESTORE_PREPARE); + if (error) + goto Thaw; + pr_debug("PM: Preparing devices for restore.\n"); suspend_console(); @@ -299,9 +317,12 @@ static int software_resume(void) device_resume(); resume_console(); Thaw: + suspend_notifier_call_chain(SUSPEND_THAW_PREPARE); + Unprepare: printk(KERN_ERR "PM: Restore failed, recovering.\n"); unprepare_processes(); Done: + suspend_notifier_call_chain(SUSPEND_FINISHED); free_basic_memory_bitmaps(); Finish: atomic_inc(&snapshot_device_available); Index: linux-2.6.21-rc6-mm1/kernel/power/main.c =================================================================== --- linux-2.6.21-rc6-mm1.orig/kernel/power/main.c 2007-04-22 19:55:59.000000000 +0200 +++ linux-2.6.21-rc6-mm1/kernel/power/main.c 2007-04-22 20:43:19.000000000 +0200 @@ -86,11 +86,20 @@ static int suspend_prepare(suspend_state pm_prepare_console(); + error = suspend_notifier_call_chain(SUSPEND_PREPARE); + if (error) + goto Finish; + if (freeze_processes()) { error = -EAGAIN; - goto Thaw; + thaw_processes(); + goto Finish; } + error = suspend_notifier_call_chain(SUSPEND_ENTER_PREPARE); + if (error) + goto Thaw; + if ((free_pages = global_page_state(NR_FREE_PAGES)) < FREE_PAGE_NUMBER) { pr_debug("PM: free some memory\n"); @@ -123,8 +132,11 @@ static int suspend_prepare(suspend_state device_resume(); resume_console(); Thaw: + suspend_notifier_call_chain(SUSPEND_THAW_PREPARE); thaw_processes(); + Finish: pm_restore_console(); + suspend_notifier_call_chain(SUSPEND_FINISHED); return error; } @@ -162,8 +174,10 @@ static void suspend_finish(suspend_state pm_finish(state); device_resume(); resume_console(); + suspend_notifier_call_chain(SUSPEND_THAW_PREPARE); thaw_processes(); pm_restore_console(); + suspend_notifier_call_chain(SUSPEND_FINISHED); } Index: linux-2.6.21-rc6-mm1/kernel/power/user.c =================================================================== --- linux-2.6.21-rc6-mm1.orig/kernel/power/user.c 2007-04-22 19:56:52.000000000 +0200 +++ linux-2.6.21-rc6-mm1/kernel/power/user.c 2007-04-22 20:46:41.000000000 +0200 @@ -75,6 +75,18 @@ static int snapshot_open(struct inode *i return 0; } +static void snapshot_unfreeze(struct snapshot_data *data) +{ + if (!data->frozen) + return; + + mutex_lock(&pm_mutex); + thaw_processes(); + suspend_notifier_call_chain(SUSPEND_FINISHED); + mutex_unlock(&pm_mutex); + data->frozen = 0; +} + static int snapshot_release(struct inode *inode, struct file *filp) { struct snapshot_data *data; @@ -83,11 +95,7 @@ static int snapshot_release(struct inode free_basic_memory_bitmaps(); data = filp->private_data; free_all_swap_pages(data->swap); - if (data->frozen) { - mutex_lock(&pm_mutex); - thaw_processes(); - mutex_unlock(&pm_mutex); - } + snapshot_unfreeze(data); atomic_inc(&snapshot_device_available); return 0; } @@ -147,6 +155,10 @@ static inline int snapshot_suspend(int p int error; mutex_lock(&pm_mutex); + error = suspend_notifier_call_chain(SUSPEND_ENTER_PREPARE); + if (error) + goto Finish; + /* Free memory before shutting down devices. */ error = swsusp_shrink_memory(); if (error) @@ -175,6 +187,7 @@ static inline int snapshot_suspend(int p device_resume(); resume_console(); Finish: + suspend_notifier_call_chain(SUSPEND_THAW_PREPARE); mutex_unlock(&pm_mutex); return error; } @@ -185,6 +198,10 @@ static inline int snapshot_restore(int p mutex_lock(&pm_mutex); pm_prepare_console(); + error = suspend_notifier_call_chain(SUSPEND_RESTORE_PREPARE); + if (error) + goto Finish; + if (platform_suspend) { error = platform_prepare(); if (error) @@ -207,6 +224,7 @@ static inline int snapshot_restore(int p device_resume(); resume_console(); Finish: + suspend_notifier_call_chain(SUSPEND_THAW_PREPARE); pm_restore_console(); mutex_unlock(&pm_mutex); return error; @@ -235,8 +253,13 @@ static int snapshot_ioctl(struct inode * if (data->frozen) break; mutex_lock(&pm_mutex); + error = suspend_notifier_call_chain(SUSPEND_PREPARE); + if (error) + break; + if (freeze_processes()) { thaw_processes(); + suspend_notifier_call_chain(SUSPEND_FINISHED); error = -EBUSY; } mutex_unlock(&pm_mutex); @@ -245,12 +268,7 @@ static int snapshot_ioctl(struct inode * break; case SNAPSHOT_UNFREEZE: - if (!data->frozen) - break; - mutex_lock(&pm_mutex); - thaw_processes(); - mutex_unlock(&pm_mutex); - data->frozen = 0; + snapshot_unfreeze(data); break; case SNAPSHOT_ATOMIC_SNAPSHOT: @@ -349,6 +367,10 @@ static int snapshot_ioctl(struct inode * break; } + error = suspend_notifier_call_chain(SUSPEND_ENTER_PREPARE); + if (error) + goto OutS3; + if (pm_ops->prepare) { error = pm_ops->prepare(PM_SUSPEND_MEM); if (error) @@ -375,6 +397,7 @@ static int snapshot_ioctl(struct inode * pm_ops->finish(PM_SUSPEND_MEM); OutS3: + suspend_notifier_call_chain(SUSPEND_THAW_PREPARE); mutex_unlock(&pm_mutex); break; Index: linux-2.6.21-rc6-mm1/Documentation/power/suspend-notifiers.txt =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux-2.6.21-rc6-mm1/Documentation/power/suspend-notifiers.txt 2007-04-22 20:25:28.000000000 +0200 @@ -0,0 +1,48 @@ +Suspend notifiers + (C) 2007 Rafael J. Wysocki <rjw@sisk.pl>, GPL + +There are some operations that device drivers may want to carry out in their +.suspend() routines, but shouldn't, because they can cause a suspend to fail. +For example, a driver may want to allocate a substantial amount of memory +(like 50 MB) in .suspend(), but that shouldn't be done after the swsusp's memory +shrinker has run. Also, there may be some operations, that subsystems may want +to carry out before a suspend or after a resume, requiring the system to be +fully functional, so the drivers' .suspend() and .resume() routines are not +suitable for this purpose. + +The subsystems that have such needs can register suspend notifiers that will be +notified of the following events by the suspend core: + +SUSPEND_PREPARE the system is going to suspend, tasks will be frozen + immediately + +SUSPEND_ENTER_PREPARE tasks have been frozen, memory is going to be freed + and devices are going to be suspended + +SUSPEND_THAW_PREPARE devices have been resumed, tasks will be thawed + immediately + +SUSPEND_FINISHED the resume is complete, the system is fully functional + +SUSPEND_RESTORE_PREPARE the system is preparing to restore the swsusp's suspend + image, tasks have been frozen and devices are going to + be suspended + +It is generally assumed that whatever the notifiers do for SUSPEND_PREPARE, +should be undone for SUSPEND_FINISHED, and what is done for +SUSPEND_ENTER_PREPARE, should be undone for SUSPEND_FINISHED (eg. if memory is +allocated for SUSPEND_ENTER_PREPARE, it should be freed for SUSPEND_FINISHED). +Moreover, if the SUSPEND_PREPARE hooks are called, SUSPEND_FINISHED will be +called too and if SUSPEND_ENTER_PREPARE are called, SUSPEND_THAW_PREPARE will be +called either, even if the suspend fails. This way, for example, the memory +allocated with SUSPEND_ENTER_PREPARE can always be freed with +SUSPEND_THAW_PREPARE and need not be leaked in case the suspend fails. + +The suspend notifiers are called with pm_mutex held. + +The suspend notifiers are defined in the usual way, but their last argument is +meaningless (it is always NULL). To register and/or unregister a suspend +notifier use the functions register_suspend_notifier() and +unregister_suspend_notifier(), respectively, defined in kernel/power/notify.c . +If you don't need to unregister the notifier, you can also use the +suspend_notifier() macro defined in include/linux/suspend.h . ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH -mm 3/3] PM: Introduce suspend notifiers (rev. 2) 2007-04-22 18:48 ` [PATCH -mm 3/3] PM: Introduce suspend notifiers (rev. 2) Rafael J. Wysocki @ 2007-04-24 10:28 ` Andrew Morton 2007-04-24 11:26 ` Rafael J. Wysocki 0 siblings, 1 reply; 6+ messages in thread From: Andrew Morton @ 2007-04-24 10:28 UTC (permalink / raw) To: Rafael J. Wysocki; +Cc: LKML, Nigel Cunningham, Pavel Machek On Sun, 22 Apr 2007 20:48:08 +0200 "Rafael J. Wysocki" <rjw@sisk.pl> wrote: > Make it possible to register suspend notifiers so that subsystems can perform > suspend-related operations that should not be carried out by device drivers' > .suspend() and .resume() routines. x86_64 allnoconfig: arch/x86_64/kernel/e820.c: In function 'e820_mark_nosave_regions': arch/x86_64/kernel/e820.c:279: warning: implicit declaration of function 'register_nosave_region' arch/x86_64/kernel/built-in.o: In function `e820_mark_nosave_regions': : undefined reference to `register_nosave_region' arch/x86_64/kernel/built-in.o: In function `e820_mark_nosave_regions': : undefined reference to `register_nosave_region' ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH -mm 3/3] PM: Introduce suspend notifiers (rev. 2) 2007-04-24 10:28 ` Andrew Morton @ 2007-04-24 11:26 ` Rafael J. Wysocki 0 siblings, 0 replies; 6+ messages in thread From: Rafael J. Wysocki @ 2007-04-24 11:26 UTC (permalink / raw) To: Andrew Morton; +Cc: LKML, Nigel Cunningham, Pavel Machek On Tuesday, 24 April 2007 12:28, Andrew Morton wrote: > On Sun, 22 Apr 2007 20:48:08 +0200 "Rafael J. Wysocki" <rjw@sisk.pl> wrote: > > > Make it possible to register suspend notifiers so that subsystems can perform > > suspend-related operations that should not be carried out by device drivers' > > .suspend() and .resume() routines. > > x86_64 allnoconfig: > > arch/x86_64/kernel/e820.c: In function 'e820_mark_nosave_regions': > arch/x86_64/kernel/e820.c:279: warning: implicit declaration of function 'register_nosave_region' > arch/x86_64/kernel/built-in.o: In function `e820_mark_nosave_regions': > : undefined reference to `register_nosave_region' > arch/x86_64/kernel/built-in.o: In function `e820_mark_nosave_regions': > : undefined reference to `register_nosave_region' Ouch, I tried to be too smart. Fixed. --- From: Rafael J. Wysocki <rjw@sisk.pl> Make it possible to register suspend notifiers so that subsystems can perform suspend-related operations that should not be carried out by device drivers' .suspend() and .resume() routines. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> --- Documentation/power/suspend-notifiers.txt | 48 ++++++++++++++++++++++++++++ include/linux/notifier.h | 6 +++ include/linux/suspend.h | 19 +++++++++++ kernel/power/Makefile | 2 - kernel/power/disk.c | 23 ++++++++++++- kernel/power/main.c | 16 ++++++++- kernel/power/notify.c | 51 ++++++++++++++++++++++++++++++ kernel/power/power.h | 3 + kernel/power/user.c | 45 ++++++++++++++++++++------ 9 files changed, 199 insertions(+), 14 deletions(-) Index: linux-2.6.21-rc6-mm1/kernel/power/notify.c =================================================================== --- /dev/null +++ linux-2.6.21-rc6-mm1/kernel/power/notify.c @@ -0,0 +1,51 @@ +/* + * linux/kernel/power/notify.c + * + * This file contains functions used for registering and calling suspend + * notifiers that can be used by subsystems for carrying out some special + * suspend-related operations. + * + * Copyright (C) 2007 Rafael J. Wysocki <rjw@sisk.pl> + * + * This file is released under the GPLv2. + * + */ + +#include <linux/smp.h> +#include <linux/notifier.h> +#include <linux/module.h> +#include <linux/suspend.h> + +static DEFINE_MUTEX(suspend_notifier_lock); + +static RAW_NOTIFIER_HEAD(suspend_chain); + +int register_suspend_notifier(struct notifier_block *nb) +{ + int ret; + mutex_lock(&suspend_notifier_lock); + ret = raw_notifier_chain_register(&suspend_chain, nb); + mutex_unlock(&suspend_notifier_lock); + return ret; +} +EXPORT_SYMBOL(register_suspend_notifier); + +void unregister_suspend_notifier(struct notifier_block *nb) +{ + mutex_lock(&suspend_notifier_lock); + raw_notifier_chain_unregister(&suspend_chain, nb); + mutex_unlock(&suspend_notifier_lock); +} +EXPORT_SYMBOL(unregister_suspend_notifier); + +int suspend_notifier_call_chain(unsigned long val) +{ + int error = 0; + + mutex_lock(&suspend_notifier_lock); + if (raw_notifier_call_chain(&suspend_chain, val, NULL) == NOTIFY_BAD) + error = -EINVAL; + + mutex_unlock(&suspend_notifier_lock); + return error; +} Index: linux-2.6.21-rc6-mm1/include/linux/suspend.h =================================================================== --- linux-2.6.21-rc6-mm1.orig/include/linux/suspend.h +++ linux-2.6.21-rc6-mm1/include/linux/suspend.h @@ -60,4 +60,23 @@ struct saved_context; void __save_processor_state(struct saved_context *ctxt); void __restore_processor_state(struct saved_context *ctxt); +#ifdef CONFIG_PM +int register_suspend_notifier(struct notifier_block *nb); +void unregister_suspend_notifier(struct notifier_block *nb); + +#define suspend_notifier(fn, pri) { \ + static struct notifier_block fn##_nb = \ + { .notifier_call = fn, .priority = pri }; \ + register_suspend_notifier(&fn##_nb); \ +} +#else /* CONFIG_PM */ +static inline int register_suspend_notifier(struct notifier_block *nb) { + return 0; +} +static inline void unregister_suspend_notifier(struct notifier_block *nb) { +} + +#define suspend_notifier(fn, pri) do { (void)(fn); } while (0) +#endif /* CONFIG_PM */ + #endif /* _LINUX_SWSUSP_H */ Index: linux-2.6.21-rc6-mm1/kernel/power/Makefile =================================================================== --- linux-2.6.21-rc6-mm1.orig/kernel/power/Makefile +++ linux-2.6.21-rc6-mm1/kernel/power/Makefile @@ -3,7 +3,7 @@ ifeq ($(CONFIG_PM_DEBUG),y) EXTRA_CFLAGS += -DDEBUG endif -obj-y := main.o process.o console.o +obj-y := main.o process.o console.o notify.o obj-$(CONFIG_PM_LEGACY) += pm.o obj-$(CONFIG_SOFTWARE_SUSPEND) += swsusp.o disk.o snapshot.o swap.o user.o Index: linux-2.6.21-rc6-mm1/kernel/power/power.h =================================================================== --- linux-2.6.21-rc6-mm1.orig/kernel/power/power.h +++ linux-2.6.21-rc6-mm1/kernel/power/power.h @@ -170,3 +170,6 @@ extern int suspend_enter(suspend_state_t struct timeval; extern void swsusp_show_speed(struct timeval *, struct timeval *, unsigned int, char *); + +/* kernel/power/notify.c */ +extern int suspend_notifier_call_chain(unsigned long val); Index: linux-2.6.21-rc6-mm1/include/linux/notifier.h =================================================================== --- linux-2.6.21-rc6-mm1.orig/include/linux/notifier.h +++ linux-2.6.21-rc6-mm1/include/linux/notifier.h @@ -209,5 +209,11 @@ extern int __srcu_notifier_call_chain(st #define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN) #define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN) +#define SUSPEND_PREPARE 0x0002 /* Going to freeze tasks */ +#define SUSPEND_ENTER_PREPARE 0x0003 /* Tasks are frozen, we are suspending */ +#define SUSPEND_THAW_PREPARE 0x0004 /* Going to thaw frozen tasks */ +#define SUSPEND_FINISHED 0x0005 /* Tasks have been thawed */ +#define SUSPEND_RESTORE_PREPARE 0x0006 /* STD restore is going to happen */ + #endif /* __KERNEL__ */ #endif /* _LINUX_NOTIFIER_H */ Index: linux-2.6.21-rc6-mm1/kernel/power/disk.c =================================================================== --- linux-2.6.21-rc6-mm1.orig/kernel/power/disk.c +++ linux-2.6.21-rc6-mm1/kernel/power/disk.c @@ -139,10 +139,18 @@ int pm_suspend_disk(void) if (error) goto Exit; + error = suspend_notifier_call_chain(SUSPEND_PREPARE); + if (error) + goto Finish; + error = prepare_processes(); if (error) goto Finish; + error = suspend_notifier_call_chain(SUSPEND_ENTER_PREPARE); + if (error) + goto Thaw; + if (pm_disk_mode == PM_DISK_TESTPROC) { printk("swsusp debug: Waiting for 5 seconds.\n"); mdelay(5000); @@ -205,8 +213,10 @@ int pm_suspend_disk(void) device_resume(); resume_console(); Thaw: + suspend_notifier_call_chain(SUSPEND_THAW_PREPARE); unprepare_processes(); Finish: + suspend_notifier_call_chain(SUSPEND_FINISHED); free_basic_memory_bitmaps(); Exit: atomic_inc(&snapshot_device_available); @@ -267,6 +277,10 @@ static int software_resume(void) if (error) goto Finish; + error = suspend_notifier_call_chain(SUSPEND_PREPARE); + if (error) + goto Done; + pr_debug("PM: Preparing processes for restore.\n"); error = prepare_processes(); if (error) { @@ -279,9 +293,13 @@ static int software_resume(void) error = swsusp_read(); if (error) { swsusp_free(); - goto Thaw; + goto Unprepare; } + error = suspend_notifier_call_chain(SUSPEND_RESTORE_PREPARE); + if (error) + goto Thaw; + pr_debug("PM: Preparing devices for restore.\n"); suspend_console(); @@ -299,9 +317,12 @@ static int software_resume(void) device_resume(); resume_console(); Thaw: + suspend_notifier_call_chain(SUSPEND_THAW_PREPARE); + Unprepare: printk(KERN_ERR "PM: Restore failed, recovering.\n"); unprepare_processes(); Done: + suspend_notifier_call_chain(SUSPEND_FINISHED); free_basic_memory_bitmaps(); Finish: atomic_inc(&snapshot_device_available); Index: linux-2.6.21-rc6-mm1/kernel/power/main.c =================================================================== --- linux-2.6.21-rc6-mm1.orig/kernel/power/main.c +++ linux-2.6.21-rc6-mm1/kernel/power/main.c @@ -86,11 +86,20 @@ static int suspend_prepare(suspend_state pm_prepare_console(); + error = suspend_notifier_call_chain(SUSPEND_PREPARE); + if (error) + goto Finish; + if (freeze_processes()) { error = -EAGAIN; - goto Thaw; + thaw_processes(); + goto Finish; } + error = suspend_notifier_call_chain(SUSPEND_ENTER_PREPARE); + if (error) + goto Thaw; + if ((free_pages = global_page_state(NR_FREE_PAGES)) < FREE_PAGE_NUMBER) { pr_debug("PM: free some memory\n"); @@ -123,8 +132,11 @@ static int suspend_prepare(suspend_state device_resume(); resume_console(); Thaw: + suspend_notifier_call_chain(SUSPEND_THAW_PREPARE); thaw_processes(); + Finish: pm_restore_console(); + suspend_notifier_call_chain(SUSPEND_FINISHED); return error; } @@ -162,8 +174,10 @@ static void suspend_finish(suspend_state pm_finish(state); device_resume(); resume_console(); + suspend_notifier_call_chain(SUSPEND_THAW_PREPARE); thaw_processes(); pm_restore_console(); + suspend_notifier_call_chain(SUSPEND_FINISHED); } Index: linux-2.6.21-rc6-mm1/kernel/power/user.c =================================================================== --- linux-2.6.21-rc6-mm1.orig/kernel/power/user.c +++ linux-2.6.21-rc6-mm1/kernel/power/user.c @@ -75,6 +75,18 @@ static int snapshot_open(struct inode *i return 0; } +static void snapshot_unfreeze(struct snapshot_data *data) +{ + if (!data->frozen) + return; + + mutex_lock(&pm_mutex); + thaw_processes(); + suspend_notifier_call_chain(SUSPEND_FINISHED); + mutex_unlock(&pm_mutex); + data->frozen = 0; +} + static int snapshot_release(struct inode *inode, struct file *filp) { struct snapshot_data *data; @@ -83,11 +95,7 @@ static int snapshot_release(struct inode free_basic_memory_bitmaps(); data = filp->private_data; free_all_swap_pages(data->swap); - if (data->frozen) { - mutex_lock(&pm_mutex); - thaw_processes(); - mutex_unlock(&pm_mutex); - } + snapshot_unfreeze(data); atomic_inc(&snapshot_device_available); return 0; } @@ -147,6 +155,10 @@ static inline int snapshot_suspend(int p int error; mutex_lock(&pm_mutex); + error = suspend_notifier_call_chain(SUSPEND_ENTER_PREPARE); + if (error) + goto Finish; + /* Free memory before shutting down devices. */ error = swsusp_shrink_memory(); if (error) @@ -175,6 +187,7 @@ static inline int snapshot_suspend(int p device_resume(); resume_console(); Finish: + suspend_notifier_call_chain(SUSPEND_THAW_PREPARE); mutex_unlock(&pm_mutex); return error; } @@ -185,6 +198,10 @@ static inline int snapshot_restore(int p mutex_lock(&pm_mutex); pm_prepare_console(); + error = suspend_notifier_call_chain(SUSPEND_RESTORE_PREPARE); + if (error) + goto Finish; + if (platform_suspend) { error = platform_prepare(); if (error) @@ -207,6 +224,7 @@ static inline int snapshot_restore(int p device_resume(); resume_console(); Finish: + suspend_notifier_call_chain(SUSPEND_THAW_PREPARE); pm_restore_console(); mutex_unlock(&pm_mutex); return error; @@ -235,8 +253,13 @@ static int snapshot_ioctl(struct inode * if (data->frozen) break; mutex_lock(&pm_mutex); + error = suspend_notifier_call_chain(SUSPEND_PREPARE); + if (error) + break; + if (freeze_processes()) { thaw_processes(); + suspend_notifier_call_chain(SUSPEND_FINISHED); error = -EBUSY; } mutex_unlock(&pm_mutex); @@ -245,12 +268,7 @@ static int snapshot_ioctl(struct inode * break; case SNAPSHOT_UNFREEZE: - if (!data->frozen) - break; - mutex_lock(&pm_mutex); - thaw_processes(); - mutex_unlock(&pm_mutex); - data->frozen = 0; + snapshot_unfreeze(data); break; case SNAPSHOT_ATOMIC_SNAPSHOT: @@ -349,6 +367,10 @@ static int snapshot_ioctl(struct inode * break; } + error = suspend_notifier_call_chain(SUSPEND_ENTER_PREPARE); + if (error) + goto OutS3; + if (pm_ops->prepare) { error = pm_ops->prepare(PM_SUSPEND_MEM); if (error) @@ -375,6 +397,7 @@ static int snapshot_ioctl(struct inode * pm_ops->finish(PM_SUSPEND_MEM); OutS3: + suspend_notifier_call_chain(SUSPEND_THAW_PREPARE); mutex_unlock(&pm_mutex); break; Index: linux-2.6.21-rc6-mm1/Documentation/power/suspend-notifiers.txt =================================================================== --- /dev/null +++ linux-2.6.21-rc6-mm1/Documentation/power/suspend-notifiers.txt @@ -0,0 +1,48 @@ +Suspend notifiers + (C) 2007 Rafael J. Wysocki <rjw@sisk.pl>, GPL + +There are some operations that device drivers may want to carry out in their +.suspend() routines, but shouldn't, because they can cause a suspend to fail. +For example, a driver may want to allocate a substantial amount of memory +(like 50 MB) in .suspend(), but that shouldn't be done after the swsusp's memory +shrinker has run. Also, there may be some operations, that subsystems may want +to carry out before a suspend or after a resume, requiring the system to be +fully functional, so the drivers' .suspend() and .resume() routines are not +suitable for this purpose. + +The subsystems that have such needs can register suspend notifiers that will be +notified of the following events by the suspend core: + +SUSPEND_PREPARE the system is going to suspend, tasks will be frozen + immediately + +SUSPEND_ENTER_PREPARE tasks have been frozen, memory is going to be freed + and devices are going to be suspended + +SUSPEND_THAW_PREPARE devices have been resumed, tasks will be thawed + immediately + +SUSPEND_FINISHED the resume is complete, the system is fully functional + +SUSPEND_RESTORE_PREPARE the system is preparing to restore the swsusp's suspend + image, tasks have been frozen and devices are going to + be suspended + +It is generally assumed that whatever the notifiers do for SUSPEND_PREPARE, +should be undone for SUSPEND_FINISHED, and what is done for +SUSPEND_ENTER_PREPARE, should be undone for SUSPEND_FINISHED (eg. if memory is +allocated for SUSPEND_ENTER_PREPARE, it should be freed for SUSPEND_FINISHED). +Moreover, if the SUSPEND_PREPARE hooks are called, SUSPEND_FINISHED will be +called too and if SUSPEND_ENTER_PREPARE are called, SUSPEND_THAW_PREPARE will be +called either, even if the suspend fails. This way, for example, the memory +allocated with SUSPEND_ENTER_PREPARE can always be freed with +SUSPEND_THAW_PREPARE and need not be leaked in case the suspend fails. + +The suspend notifiers are called with pm_mutex held. + +The suspend notifiers are defined in the usual way, but their last argument is +meaningless (it is always NULL). To register and/or unregister a suspend +notifier use the functions register_suspend_notifier() and +unregister_suspend_notifier(), respectively, defined in kernel/power/notify.c . +If you don't need to unregister the notifier, you can also use the +suspend_notifier() macro defined in include/linux/suspend.h . ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2007-04-24 11:22 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2007-04-22 18:10 [PATCH -mm 0/3] Suspend notifiers Rafael J. Wysocki 2007-04-22 18:12 ` [PATCH -mm 1/3] swsusp: Fix snapshot_release Rafael J. Wysocki 2007-04-22 18:14 ` [PATCH -mm 2/3] swsusp: Free more memory Rafael J. Wysocki 2007-04-22 18:48 ` [PATCH -mm 3/3] PM: Introduce suspend notifiers (rev. 2) Rafael J. Wysocki 2007-04-24 10:28 ` Andrew Morton 2007-04-24 11:26 ` Rafael J. Wysocki
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