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| author | Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> | 2011-12-06 23:24:38 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rjw@sisk.pl> | 2011-12-08 23:22:21 +0100 |
| commit | 9b6fc5dc879bc90f765db0e95eefcf123d0d06dd (patch) | |
| tree | 1ccae80c48070963c2296a6e4c6d98107a0efbbf /include/linux | |
| parent | 33e638b9070ba5e8812836e20390da6a6af13900 (diff) | |
| download | lwn-9b6fc5dc879bc90f765db0e95eefcf123d0d06dd.tar.gz lwn-9b6fc5dc879bc90f765db0e95eefcf123d0d06dd.zip | |
PM / Sleep: Make [un]lock_system_sleep() generic
The [un]lock_system_sleep() APIs were originally introduced to mutually
exclude memory hotplug and hibernation.
Directly using mutex_lock(&pm_mutex) to achieve mutual exclusion with
suspend or hibernation code can lead to freezing failures. However, the
APIs [un]lock_system_sleep() can be safely used to achieve the same,
without causing freezing failures.
So, since it would be beneficial to modify all the existing users of
mutex_lock(&pm_mutex) (in all parts of the kernel), so that they use these
safe APIs intead, make these APIs generic by removing the restriction that
they work only when CONFIG_HIBERNATE_CALLBACKS is set. Moreover, that
restriction didn't buy us anything anyway.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/suspend.h | 36 |
1 files changed, 16 insertions, 20 deletions
diff --git a/include/linux/suspend.h b/include/linux/suspend.h index 906d62cfc15c..95040cc33107 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -332,6 +332,8 @@ static inline bool system_entering_hibernation(void) { return false; } #define PM_RESTORE_PREPARE 0x0005 /* Going to restore a saved image */ #define PM_POST_RESTORE 0x0006 /* Restore failed */ +extern struct mutex pm_mutex; + #ifdef CONFIG_PM_SLEEP void save_processor_state(void); void restore_processor_state(void); @@ -352,6 +354,19 @@ extern bool events_check_enabled; extern bool pm_wakeup_pending(void); extern bool pm_get_wakeup_count(unsigned int *count); extern bool pm_save_wakeup_count(unsigned int count); + +static inline void lock_system_sleep(void) +{ + freezer_do_not_count(); + mutex_lock(&pm_mutex); +} + +static inline void unlock_system_sleep(void) +{ + mutex_unlock(&pm_mutex); + freezer_count(); +} + #else /* !CONFIG_PM_SLEEP */ static inline int register_pm_notifier(struct notifier_block *nb) @@ -367,30 +382,11 @@ static inline int unregister_pm_notifier(struct notifier_block *nb) #define pm_notifier(fn, pri) do { (void)(fn); } while (0) static inline bool pm_wakeup_pending(void) { return false; } -#endif /* !CONFIG_PM_SLEEP */ - -extern struct mutex pm_mutex; -#ifndef CONFIG_HIBERNATE_CALLBACKS static inline void lock_system_sleep(void) {} static inline void unlock_system_sleep(void) {} -#else - -/* Let some subsystems like memory hotadd exclude hibernation */ - -static inline void lock_system_sleep(void) -{ - freezer_do_not_count(); - mutex_lock(&pm_mutex); -} - -static inline void unlock_system_sleep(void) -{ - mutex_unlock(&pm_mutex); - freezer_count(); -} -#endif +#endif /* !CONFIG_PM_SLEEP */ #ifdef CONFIG_ARCH_SAVE_PAGE_KEYS /* |