diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-power | 13 | ||||
| -rw-r--r-- | include/linux/suspend.h | 2 | ||||
| -rw-r--r-- | kernel/power/Kconfig | 5 | ||||
| -rw-r--r-- | kernel/power/main.c | 33 | ||||
| -rw-r--r-- | kernel/power/suspend.c | 2 |
5 files changed, 53 insertions, 2 deletions
diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power index 6f87b9dd384b..5e6ead29124c 100644 --- a/Documentation/ABI/testing/sysfs-power +++ b/Documentation/ABI/testing/sysfs-power @@ -407,3 +407,16 @@ Contact: Kalesh Singh <kaleshsingh96@gmail.com> Description: The /sys/power/suspend_stats/last_failed_step file contains the last failed step in the suspend/resume path. + +What: /sys/power/sync_on_suspend +Date: October 2019 +Contact: Jonas Meurer <jonas@freesources.org> +Description: + This file controls whether or not the kernel will sync() + filesystems during system suspend (after freezing user space + and before suspending devices). + + Writing a "1" to this file enables the sync() and writing a "0" + disables it. Reads from the file return the current value. + The default is "1" if the build-time "SUSPEND_SKIP_SYNC" config + flag is unset, or "0" otherwise. diff --git a/include/linux/suspend.h b/include/linux/suspend.h index 6fc8843f1c9e..4a230c2f1c31 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -329,6 +329,7 @@ extern void arch_suspend_disable_irqs(void); extern void arch_suspend_enable_irqs(void); extern int pm_suspend(suspend_state_t state); +extern bool sync_on_suspend_enabled; #else /* !CONFIG_SUSPEND */ #define suspend_valid_only_mem NULL @@ -342,6 +343,7 @@ static inline bool pm_suspend_default_s2idle(void) { return false; } static inline void suspend_set_ops(const struct platform_suspend_ops *ops) {} static inline int pm_suspend(suspend_state_t state) { return -ENOSYS; } +static inline bool sync_on_suspend_enabled(void) { return true; } static inline bool idle_should_enter_s2idle(void) { return false; } static inline void __init pm_states_init(void) {} static inline void s2idle_set_ops(const struct platform_s2idle_ops *ops) {} diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index d3667b4075c1..7cbfbeacd68a 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -27,7 +27,10 @@ config SUSPEND_SKIP_SYNC Skip the kernel sys_sync() before freezing user processes. Some systems prefer not to pay this cost on every invocation of suspend, or they are content with invoking sync() from - user-space before invoking suspend. Say Y if that's your case. + user-space before invoking suspend. There's a run-time switch + at '/sys/power/sync_on_suspend' to configure this behaviour. + This setting changes the default for the run-tim switch. Say Y + to change the default to disable the kernel sys_sync(). config HIBERNATE_CALLBACKS bool diff --git a/kernel/power/main.c b/kernel/power/main.c index e26de7af520b..69b7a8aeca3b 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -190,6 +190,38 @@ static ssize_t mem_sleep_store(struct kobject *kobj, struct kobj_attribute *attr } power_attr(mem_sleep); + +/* + * sync_on_suspend: invoke ksys_sync_helper() before suspend. + * + * show() returns whether ksys_sync_helper() is invoked before suspend. + * store() accepts 0 or 1. 0 disables ksys_sync_helper() and 1 enables it. + */ +bool sync_on_suspend_enabled = !IS_ENABLED(CONFIG_SUSPEND_SKIP_SYNC); + +static ssize_t sync_on_suspend_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", sync_on_suspend_enabled); +} + +static ssize_t sync_on_suspend_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t n) +{ + unsigned long val; + + if (kstrtoul(buf, 10, &val)) + return -EINVAL; + + if (val > 1) + return -EINVAL; + + sync_on_suspend_enabled = !!val; + return n; +} + +power_attr(sync_on_suspend); #endif /* CONFIG_SUSPEND */ #ifdef CONFIG_PM_SLEEP_DEBUG @@ -855,6 +887,7 @@ static struct attribute * g[] = { &wakeup_count_attr.attr, #ifdef CONFIG_SUSPEND &mem_sleep_attr.attr, + &sync_on_suspend_attr.attr, #endif #ifdef CONFIG_PM_AUTOSLEEP &autosleep_attr.attr, diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index f3b7239f1892..2c47280fbfc7 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -564,7 +564,7 @@ static int enter_state(suspend_state_t state) if (state == PM_SUSPEND_TO_IDLE) s2idle_begin(); - if (!IS_ENABLED(CONFIG_SUSPEND_SKIP_SYNC)) { + if (sync_on_suspend_enabled) { trace_suspend_resume(TPS("sync_filesystems"), 0, true); ksys_sync_helper(); trace_suspend_resume(TPS("sync_filesystems"), 0, false); |