From 9cd9d3fdd72b21b9ea47a8e1a08959d833b6e6ef Mon Sep 17 00:00:00 2001 From: Zihuan Zhang Date: Thu, 24 Apr 2025 14:03:39 +0800 Subject: PM: sleep: Remove unnecessary !! Since initcall_debug is a bool variable, it is not necessary to convert it to bool with the help of a double logical negation (!!). Remove the redundant operation. Signed-off-by: Zihuan Zhang Link: https://patch.msgid.link/20250424060339.73119-1-zhangzihuan@kylinos.cn [ rjw: Changelog rewrite ] Signed-off-by: Rafael J. Wysocki --- kernel/power/main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/power/main.c') diff --git a/kernel/power/main.c b/kernel/power/main.c index 6254814d4817..97746f08b762 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -594,7 +594,7 @@ power_attr(pm_print_times); static inline void pm_print_times_init(void) { - pm_print_times_enabled = !!initcall_debug; + pm_print_times_enabled = initcall_debug; } static ssize_t pm_wakeup_irq_show(struct kobject *kobj, -- cgit v1.2.3 From eacfbf74196f91e4c26d9f8c78e1576c1225cd8c Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Wed, 2 Apr 2025 16:07:33 +0200 Subject: power: freeze filesystems during suspend/resume Now all the pieces are in place to actually allow the power subsystem to freeze/thaw filesystems during suspend/resume. Filesystems are only frozen and thawed if the power subsystem does actually own the freeze. We could bubble up errors and fail suspend/resume if the error isn't EBUSY (aka it's already frozen) but I don't think that this is worth it. Filesystem freezing during suspend/resume is best-effort. If the user has 500 ext4 filesystems mounted and 4 fail to freeze for whatever reason then we simply skip them. What we have now is already a big improvement and let's see how we fare with it before making our lives even harder (and uglier) than we have to. We add a new sysctl know /sys/power/freeze_filesystems that will allow userspace to freeze filesystems during suspend/hibernate. For now it defaults to off. The thaw logic doesn't require checking whether freezing is enabled because the power subsystem exclusively owns frozen filesystems for the duration of suspend/hibernate and is able to skip filesystems it doesn't need to freeze. Also it is technically possible that filesystem filesystem_freeze_enabled is true and power freezes the filesystems but before freezing all processes another process disables filesystem_freeze_enabled. If power were to place the filesystems_thaw() call under filesystems_freeze_enabled it would fail to thaw the fileystems it frozw. The exclusive holder mechanism makes it possible to iterate through the list without any concern making sure that no filesystems are left frozen. Link: https://lore.kernel.org/r/20250402-work-freeze-v2-3-6719a97b52ac@kernel.org Signed-off-by: Christian Brauner --- kernel/power/hibernate.c | 16 +++++++++++++++- kernel/power/main.c | 31 +++++++++++++++++++++++++++++++ kernel/power/power.h | 4 ++++ kernel/power/suspend.c | 7 +++++++ 4 files changed, 57 insertions(+), 1 deletion(-) (limited to 'kernel/power/main.c') diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 23c0f4e6cb2f..338c9917d4ee 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -778,6 +778,8 @@ int hibernate(void) goto Restore; ksys_sync_helper(); + if (filesystem_freeze_enabled) + filesystems_freeze(); error = freeze_processes(); if (error) @@ -846,6 +848,7 @@ int hibernate(void) /* Don't bother checking whether freezer_test_done is true */ freezer_test_done = false; Exit: + filesystems_thaw(); pm_notifier_call_chain(PM_POST_HIBERNATION); Restore: pm_restore_console(); @@ -882,6 +885,9 @@ int hibernate_quiet_exec(int (*func)(void *data), void *data) if (error) goto restore; + if (filesystem_freeze_enabled) + filesystems_freeze(); + error = freeze_processes(); if (error) goto exit; @@ -941,6 +947,7 @@ thaw: thaw_processes(); exit: + filesystems_thaw(); pm_notifier_call_chain(PM_POST_HIBERNATION); restore: @@ -1029,19 +1036,26 @@ static int software_resume(void) if (error) goto Restore; + if (filesystem_freeze_enabled) + filesystems_freeze(); + pm_pr_dbg("Preparing processes for hibernation restore.\n"); error = freeze_processes(); - if (error) + if (error) { + filesystems_thaw(); goto Close_Finish; + } error = freeze_kernel_threads(); if (error) { thaw_processes(); + filesystems_thaw(); goto Close_Finish; } error = load_image_and_restore(); thaw_processes(); + filesystems_thaw(); Finish: pm_notifier_call_chain(PM_POST_RESTORE); Restore: diff --git a/kernel/power/main.c b/kernel/power/main.c index 6254814d4817..0b0e76324c43 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -962,6 +962,34 @@ power_attr(pm_freeze_timeout); #endif /* CONFIG_FREEZER*/ +#if defined(CONFIG_SUSPEND) || defined(CONFIG_HIBERNATION) +bool filesystem_freeze_enabled = false; + +static ssize_t freeze_filesystems_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%d\n", filesystem_freeze_enabled); +} + +static ssize_t freeze_filesystems_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; + + filesystem_freeze_enabled = !!val; + return n; +} + +power_attr(freeze_filesystems); +#endif /* CONFIG_SUSPEND || CONFIG_HIBERNATION */ + static struct attribute * g[] = { &state_attr.attr, #ifdef CONFIG_PM_TRACE @@ -991,6 +1019,9 @@ static struct attribute * g[] = { #endif #ifdef CONFIG_FREEZER &pm_freeze_timeout_attr.attr, +#endif +#if defined(CONFIG_SUSPEND) || defined(CONFIG_HIBERNATION) + &freeze_filesystems_attr.attr, #endif NULL, }; diff --git a/kernel/power/power.h b/kernel/power/power.h index c352dea2f67b..2eb81662b8fa 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -18,6 +18,10 @@ struct swsusp_info { unsigned long size; } __aligned(PAGE_SIZE); +#if defined(CONFIG_SUSPEND) || defined(CONFIG_HIBERNATION) +extern bool filesystem_freeze_enabled; +#endif + #ifdef CONFIG_HIBERNATION /* kernel/power/snapshot.c */ extern void __init hibernate_reserved_size_init(void); diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 8eaec4ab121d..76b141b9aac0 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -30,6 +30,7 @@ #include #include #include +#include #include "power.h" @@ -374,6 +375,8 @@ static int suspend_prepare(suspend_state_t state) if (error) goto Restore; + if (filesystem_freeze_enabled) + filesystems_freeze(); trace_suspend_resume(TPS("freeze_processes"), 0, true); error = suspend_freeze_processes(); trace_suspend_resume(TPS("freeze_processes"), 0, false); @@ -550,6 +553,7 @@ int suspend_devices_and_enter(suspend_state_t state) static void suspend_finish(void) { suspend_thaw_processes(); + filesystems_thaw(); pm_notifier_call_chain(PM_POST_SUSPEND); pm_restore_console(); } @@ -588,6 +592,8 @@ static int enter_state(suspend_state_t state) ksys_sync_helper(); trace_suspend_resume(TPS("sync_filesystems"), 0, false); } + if (filesystem_freeze_enabled) + filesystems_freeze(); pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels[state]); pm_suspend_clear_flags(); @@ -609,6 +615,7 @@ static int enter_state(suspend_state_t state) pm_pr_dbg("Finishing wakeup.\n"); suspend_finish(); Unlock: + filesystems_thaw(); mutex_unlock(&system_transition_mutex); return error; } -- cgit v1.2.3 From 1b17d4525bca3916644c41e01522df8fa0f8b90b Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 9 May 2025 14:51:47 +0200 Subject: PM: sleep: Print PM debug messages during hibernation Commit cdb8c100d8a4 ("include/linux/suspend.h: Only show pm_pr_dbg messages at suspend/resume") caused PM debug messages to only be printed during system-wide suspend and resume in progress, but it forgot about hibernation. Address this by adding a check for hibernation in progress to pm_debug_messages_should_print(). Fixes: cdb8c100d8a4 ("include/linux/suspend.h: Only show pm_pr_dbg messages at suspend/resume") Signed-off-by: Rafael J. Wysocki Reviewed-by: Mario Limonciello Link: https://patch.msgid.link/4998903.GXAFRqVoOG@rjwysocki.net --- kernel/power/hibernate.c | 5 +++++ kernel/power/main.c | 3 ++- kernel/power/power.h | 4 ++++ 3 files changed, 11 insertions(+), 1 deletion(-) (limited to 'kernel/power/main.c') diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index f4db2e82fd87..c503baf170af 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -90,6 +90,11 @@ void hibernate_release(void) atomic_inc(&hibernate_atomic); } +bool hibernation_in_progress(void) +{ + return !atomic_read(&hibernate_atomic); +} + bool hibernation_available(void) { return nohibernate == 0 && diff --git a/kernel/power/main.c b/kernel/power/main.c index 97746f08b762..fb20a6e26fb6 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -613,7 +613,8 @@ bool pm_debug_messages_on __read_mostly; bool pm_debug_messages_should_print(void) { - return pm_debug_messages_on && pm_suspend_target_state != PM_SUSPEND_ON; + return pm_debug_messages_on && (hibernation_in_progress() || + pm_suspend_target_state != PM_SUSPEND_ON); } EXPORT_SYMBOL_GPL(pm_debug_messages_should_print); diff --git a/kernel/power/power.h b/kernel/power/power.h index c352dea2f67b..f8496f40b54f 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -71,10 +71,14 @@ extern void enable_restore_image_protection(void); static inline void enable_restore_image_protection(void) {} #endif /* CONFIG_STRICT_KERNEL_RWX */ +extern bool hibernation_in_progress(void); + #else /* !CONFIG_HIBERNATION */ static inline void hibernate_reserved_size_init(void) {} static inline void hibernate_image_size_init(void) {} + +static inline bool hibernation_in_progress(void) { return false; } #endif /* !CONFIG_HIBERNATION */ #define power_attr(_name) \ -- cgit v1.2.3 From 34a364ff04e960a4d47f558acf7fbafcc3085c1f Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 9 May 2025 15:02:27 +0200 Subject: PM: sleep: Introduce pm_suspend_in_progress() Introduce pm_suspend_in_progress() to be used for checking if a system- wide suspend or resume transition is in progress, instead of comparing pm_suspend_target_state directly to PM_SUSPEND_ON, and use it where applicable. No intentional functional impact. Signed-off-by: Rafael J. Wysocki Reviewed-by: Rodrigo Vivi Acked-by: Rodrigo Vivi Reviewed-by: Raag Jadav Reviewed-by: Mario Limonciello Link: https://patch.msgid.link/2020901.PYKUYFuaPT@rjwysocki.net --- arch/x86/pci/fixup.c | 4 ++-- drivers/base/power/wakeup.c | 2 +- drivers/gpu/drm/xe/xe_pm.c | 2 +- include/linux/suspend.h | 5 +++++ kernel/power/main.c | 4 ++-- 5 files changed, 11 insertions(+), 6 deletions(-) (limited to 'kernel/power/main.c') diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c index efefeb82ab61..e8ee1afa1992 100644 --- a/arch/x86/pci/fixup.c +++ b/arch/x86/pci/fixup.c @@ -970,13 +970,13 @@ static void amd_rp_pme_suspend(struct pci_dev *dev) struct pci_dev *rp; /* - * PM_SUSPEND_ON means we're doing runtime suspend, which means + * If system suspend is not in progress, we're doing runtime suspend, so * amd-pmc will not be involved so PMEs during D3 work as advertised. * * The PMEs *do* work if amd-pmc doesn't put the SoC in the hardware * sleep state, but we assume amd-pmc is always present. */ - if (pm_suspend_target_state == PM_SUSPEND_ON) + if (!pm_suspend_in_progress()) return; rp = pcie_find_root_port(dev); diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c index 63bf914a4d44..6f6f309817f4 100644 --- a/drivers/base/power/wakeup.c +++ b/drivers/base/power/wakeup.c @@ -337,7 +337,7 @@ int device_wakeup_enable(struct device *dev) if (!dev || !dev->power.can_wakeup) return -EINVAL; - if (pm_suspend_target_state != PM_SUSPEND_ON) + if (pm_suspend_in_progress()) dev_dbg(dev, "Suspicious %s() during system transition!\n", __func__); ws = wakeup_source_register(dev, dev_name(dev)); diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c index 7b6b754ad6eb..cb7fbf74138e 100644 --- a/drivers/gpu/drm/xe/xe_pm.c +++ b/drivers/gpu/drm/xe/xe_pm.c @@ -641,7 +641,7 @@ static bool xe_pm_suspending_or_resuming(struct xe_device *xe) return dev->power.runtime_status == RPM_SUSPENDING || dev->power.runtime_status == RPM_RESUMING || - pm_suspend_target_state != PM_SUSPEND_ON; + pm_suspend_in_progress(); #else return false; #endif diff --git a/include/linux/suspend.h b/include/linux/suspend.h index da6ebca3ff77..52ea108f9451 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -298,6 +298,11 @@ static inline void s2idle_set_ops(const struct platform_s2idle_ops *ops) {} static inline void s2idle_wake(void) {} #endif /* !CONFIG_SUSPEND */ +static inline bool pm_suspend_in_progress(void) +{ + return pm_suspend_target_state != PM_SUSPEND_ON; +} + /* struct pbe is used for creating lists of pages that should be restored * atomically during the resume from disk, because the page frames they have * occupied before the suspend are in use. diff --git a/kernel/power/main.c b/kernel/power/main.c index fb20a6e26fb6..8c26241c6724 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -613,8 +613,8 @@ bool pm_debug_messages_on __read_mostly; bool pm_debug_messages_should_print(void) { - return pm_debug_messages_on && (hibernation_in_progress() || - pm_suspend_target_state != PM_SUSPEND_ON); + return pm_debug_messages_on && (pm_suspend_in_progress() || + hibernation_in_progress()); } EXPORT_SYMBOL_GPL(pm_debug_messages_should_print); -- cgit v1.2.3 From f5c0ecf196aaf78777f1606f1e0392c5e57c4530 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 9 May 2025 15:03:35 +0200 Subject: PM: sleep: Introduce pm_sleep_transition_in_progress() The "suspend in progress" check in device_wakeup_enable() does not cover hibernation, but arguably it should do that, so introduce pm_sleep_transition_in_progress() covering transitions during both system suspend and hibernation to use in there and use it also in pm_debug_messages_should_print(). Signed-off-by: Rafael J. Wysocki Reviewed-by: Mario Limonciello Link: https://patch.msgid.link/7820474.EvYhyI6sBW@rjwysocki.net [ rjw: Move the new function definition under CONFIG_PM_SLEEP ] Signed-off-by: Rafael J. Wysocki --- drivers/base/power/wakeup.c | 2 +- include/linux/suspend.h | 4 ++++ kernel/power/main.c | 7 +++++-- 3 files changed, 10 insertions(+), 3 deletions(-) (limited to 'kernel/power/main.c') diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c index 6f6f309817f4..7e612977be1b 100644 --- a/drivers/base/power/wakeup.c +++ b/drivers/base/power/wakeup.c @@ -337,7 +337,7 @@ int device_wakeup_enable(struct device *dev) if (!dev || !dev->power.can_wakeup) return -EINVAL; - if (pm_suspend_in_progress()) + if (pm_sleep_transition_in_progress()) dev_dbg(dev, "Suspicious %s() during system transition!\n", __func__); ws = wakeup_source_register(dev, dev_name(dev)); diff --git a/include/linux/suspend.h b/include/linux/suspend.h index 52ea108f9451..b1c76c8f2c82 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -475,6 +475,8 @@ extern void pm_print_active_wakeup_sources(void); extern unsigned int lock_system_sleep(void); extern void unlock_system_sleep(unsigned int); +extern bool pm_sleep_transition_in_progress(void); + #else /* !CONFIG_PM_SLEEP */ static inline int register_pm_notifier(struct notifier_block *nb) @@ -503,6 +505,8 @@ static inline void pm_system_irq_wakeup(unsigned int irq_number) {} static inline unsigned int lock_system_sleep(void) { return 0; } static inline void unlock_system_sleep(unsigned int flags) {} +static inline bool pm_sleep_transition_in_progress(void) { return false; } + #endif /* !CONFIG_PM_SLEEP */ #ifdef CONFIG_PM_SLEEP_DEBUG diff --git a/kernel/power/main.c b/kernel/power/main.c index 8c26241c6724..8d17de9c8416 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -557,6 +557,10 @@ static int __init pm_debugfs_init(void) late_initcall(pm_debugfs_init); #endif /* CONFIG_DEBUG_FS */ +bool pm_sleep_transition_in_progress(void) +{ + return pm_suspend_in_progress() || hibernation_in_progress(); +} #endif /* CONFIG_PM_SLEEP */ #ifdef CONFIG_PM_SLEEP_DEBUG @@ -613,8 +617,7 @@ bool pm_debug_messages_on __read_mostly; bool pm_debug_messages_should_print(void) { - return pm_debug_messages_on && (pm_suspend_in_progress() || - hibernation_in_progress()); + return pm_debug_messages_on && pm_sleep_transition_in_progress(); } EXPORT_SYMBOL_GPL(pm_debug_messages_should_print); -- cgit v1.2.3