From 8a62ffe2753a845272f4f2100b5fca0b6053ff6f Mon Sep 17 00:00:00 2001 From: Vincent Guittot Date: Fri, 21 Dec 2018 11:33:54 +0100 Subject: PM-runtime: Add new interface to get accounted time Some drivers (like i915/drm) needs to get the accounted suspended time. pm_runtime_suspended_time() will return the suspended accounted time in ns unit. Reviewed-by: Ulf Hansson Signed-off-by: Vincent Guittot Signed-off-by: Rafael J. Wysocki --- drivers/base/power/runtime.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'drivers/base/power/runtime.c') diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 457be03b744d..a453090c9449 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -88,6 +88,21 @@ static void __update_runtime_status(struct device *dev, enum rpm_status status) dev->power.runtime_status = status; } +u64 pm_runtime_suspended_time(struct device *dev) +{ + unsigned long flags, time; + + spin_lock_irqsave(&dev->power.lock, flags); + + update_pm_runtime_accounting(dev); + time = dev->power.suspended_jiffies; + + spin_unlock_irqrestore(&dev->power.lock, flags); + + return jiffies_to_nsecs(time); +} +EXPORT_SYMBOL_GPL(pm_runtime_suspended_time); + /** * pm_runtime_deactivate_timer - Deactivate given device's suspend timer. * @dev: Device to handle. -- cgit v1.2.3 From 58456488e0e3793f2f95a3d2e2a78b6eba0ad0aa Mon Sep 17 00:00:00 2001 From: Vincent Guittot Date: Wed, 23 Jan 2019 08:50:13 +0100 Subject: PM-runtime: update accounting_timestamp on enable Initializing accounting_timestamp to something different from 0 during pm_runtime_init() doesn't make sense and puts an artificial ordering constraint between timekeeping_init() and pm_runtime_init(). PM-runtime should start time accounting only when it is enabled and discard the period when disabled. Set accounting_timestamp to now when enabling PM-runtime. Suggested-by: "Rafael J. Wysocki" Signed-off-by: Vincent Guittot Reviewed-by: Ulf Hansson [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki --- drivers/base/power/runtime.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'drivers/base/power/runtime.c') diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index a453090c9449..f23b7ecfce3b 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -1309,10 +1309,15 @@ void pm_runtime_enable(struct device *dev) spin_lock_irqsave(&dev->power.lock, flags); - if (dev->power.disable_depth > 0) + if (dev->power.disable_depth > 0) { dev->power.disable_depth--; - else + + /* About to enable runtime pm, set accounting_timestamp to now */ + if (!dev->power.disable_depth) + dev->power.accounting_timestamp = jiffies; + } else { dev_warn(dev, "Unbalanced %s!\n", __func__); + } WARN(!dev->power.disable_depth && dev->power.runtime_status == RPM_SUSPENDED && @@ -1509,7 +1514,7 @@ void pm_runtime_init(struct device *dev) dev->power.request_pending = false; dev->power.request = RPM_REQ_NONE; dev->power.deferred_resume = false; - dev->power.accounting_timestamp = jiffies; + dev->power.accounting_timestamp = 0; INIT_WORK(&dev->power.work, pm_runtime_work); dev->power.timer_expires = 0; -- cgit v1.2.3 From a08c2a5a31941131c41feaa0429e4c8854cf48f2 Mon Sep 17 00:00:00 2001 From: Thara Gopinath Date: Wed, 23 Jan 2019 08:50:14 +0100 Subject: PM-runtime: Replace jiffies-based accounting with ktime-based accounting Replace jiffies-based accounting for runtime_active_time and runtime_suspended_time with ktime-based accounting. This makes the runtime debug counters inline with genpd and other PM subsytems which use ktime-based accounting. Timekeeping is initialized before driver_init(). It's only at that time that PM-runtime can be enabled. Signed-off-by: Thara Gopinath [switch from ktime to raw nsec] Signed-off-by: Vincent Guittot Reviewed-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki --- drivers/base/power/runtime.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) (limited to 'drivers/base/power/runtime.c') diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index f23b7ecfce3b..eb1a3b878e1e 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -66,8 +66,8 @@ static int rpm_suspend(struct device *dev, int rpmflags); */ void update_pm_runtime_accounting(struct device *dev) { - unsigned long now = jiffies; - unsigned long delta; + u64 now = ktime_to_ns(ktime_get()); + u64 delta; delta = now - dev->power.accounting_timestamp; @@ -77,9 +77,9 @@ void update_pm_runtime_accounting(struct device *dev) return; if (dev->power.runtime_status == RPM_SUSPENDED) - dev->power.suspended_jiffies += delta; + dev->power.suspended_time += delta; else - dev->power.active_jiffies += delta; + dev->power.active_time += delta; } static void __update_runtime_status(struct device *dev, enum rpm_status status) @@ -90,16 +90,17 @@ static void __update_runtime_status(struct device *dev, enum rpm_status status) u64 pm_runtime_suspended_time(struct device *dev) { - unsigned long flags, time; + u64 time; + unsigned long flags; spin_lock_irqsave(&dev->power.lock, flags); update_pm_runtime_accounting(dev); - time = dev->power.suspended_jiffies; + time = dev->power.suspended_time; spin_unlock_irqrestore(&dev->power.lock, flags); - return jiffies_to_nsecs(time); + return time; } EXPORT_SYMBOL_GPL(pm_runtime_suspended_time); @@ -1314,7 +1315,7 @@ void pm_runtime_enable(struct device *dev) /* About to enable runtime pm, set accounting_timestamp to now */ if (!dev->power.disable_depth) - dev->power.accounting_timestamp = jiffies; + dev->power.accounting_timestamp = ktime_to_ns(ktime_get()); } else { dev_warn(dev, "Unbalanced %s!\n", __func__); } -- cgit v1.2.3 From f800ea320c09fbc8bf15aecd5c05e8e6b27ae64e Mon Sep 17 00:00:00 2001 From: Ladislav Michl Date: Wed, 30 Jan 2019 22:40:17 +0100 Subject: PM-runtime: Optimize pm_runtime_autosuspend_expiration() pm_runtime_autosuspend_expiration calls ktime_get_mono_fast_ns() even when its returned value may be unused. Therefore get the current time later and remove gotos while there. Signed-off-by: Ladislav Michl Acked-by: Tony Lindgren Acked-by: Vincent Guittot Signed-off-by: Rafael J. Wysocki --- drivers/base/power/runtime.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) (limited to 'drivers/base/power/runtime.c') diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 4eaf166d7de1..1caa3944898f 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -145,24 +145,21 @@ static void pm_runtime_cancel_pending(struct device *dev) u64 pm_runtime_autosuspend_expiration(struct device *dev) { int autosuspend_delay; - u64 last_busy, expires = 0; - u64 now = ktime_get_mono_fast_ns(); + u64 expires; if (!dev->power.use_autosuspend) - goto out; + return 0; autosuspend_delay = READ_ONCE(dev->power.autosuspend_delay); if (autosuspend_delay < 0) - goto out; - - last_busy = READ_ONCE(dev->power.last_busy); + return 0; - expires = last_busy + (u64)autosuspend_delay * NSEC_PER_MSEC; - if (expires <= now) - expires = 0; /* Already expired. */ + expires = READ_ONCE(dev->power.last_busy); + expires += (u64)autosuspend_delay * NSEC_PER_MSEC; + if (expires > ktime_get_mono_fast_ns()) + return expires; /* Expires in the future */ - out: - return expires; + return 0; } EXPORT_SYMBOL_GPL(pm_runtime_autosuspend_expiration); -- cgit v1.2.3 From c155f6499f9797f200aa46eb3ccbf198f4206970 Mon Sep 17 00:00:00 2001 From: Vincent Guittot Date: Mon, 4 Feb 2019 17:25:52 +0100 Subject: PM-runtime: Switch accounting over to ktime_get_mono_fast_ns() Similar to what happened whith autosuspend, a deadlock has been reported with PM-runtime accounting in the call path: change_clocksource ... write_seqcount_begin ... timekeeping_update ... sh_cmt_clocksource_enable ... rpm_resume update_pm_runtime_accounting ktime_get do read_seqcount_begin while read_seqcount_retry .... write_seqcount_end Make PM-runtime accounting use ktime_get_mono_fast_ns() to avoid this problem. With ktime_get_mono_fast_ns(), the timestamp is not guaranteed to be monotonic across an update of timekeeping and as a result time can go backward. Add a test to skip accounting for such situation which should stay exceptional. Fixes: a08c2a5a3194 ("PM-runtime: Replace jiffies-based accounting with ktime-based accounting") Reported-by: Biju Das Signed-off-by: Vincent Guittot Reviewed-by: Ulf Hansson [ rjw: Subject, changelog, comment cleanup ] Signed-off-by: Rafael J. Wysocki --- drivers/base/power/runtime.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) (limited to 'drivers/base/power/runtime.c') diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 1caa3944898f..6a58bb77a018 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -66,13 +66,22 @@ static int rpm_suspend(struct device *dev, int rpmflags); */ void update_pm_runtime_accounting(struct device *dev) { - u64 now = ktime_to_ns(ktime_get()); + u64 now = ktime_get_mono_fast_ns(); + u64 last = dev->power.accounting_timestamp; u64 delta; - delta = now - dev->power.accounting_timestamp; - dev->power.accounting_timestamp = now; + /* + * Because ktime_get_mono_fast_ns() is not monotonic during + * timekeeping updates, ensure that 'now' is after the last saved + * timesptamp. + */ + if (now < last) + return; + + delta = now - last; + if (dev->power.disable_depth > 0) return; @@ -1312,7 +1321,7 @@ void pm_runtime_enable(struct device *dev) /* About to enable runtime pm, set accounting_timestamp to now */ if (!dev->power.disable_depth) - dev->power.accounting_timestamp = ktime_to_ns(ktime_get()); + dev->power.accounting_timestamp = ktime_get_mono_fast_ns(); } else { dev_warn(dev, "Unbalanced %s!\n", __func__); } -- cgit v1.2.3 From fed7e88c0702e30fcd55563ca6eecd548a5d13af Mon Sep 17 00:00:00 2001 From: Vincent Guittot Date: Mon, 4 Feb 2019 17:25:53 +0100 Subject: PM-runtime: update time accounting only when enabled Update the accounting_timestamp field only when PM runtime is enabled and don't forget to account the last state before disabling it. Suggested-by: Ulf Hansson Signed-off-by: Vincent Guittot Reviewed-by: Ulf Hansson [ rjw: Minor cleanups ] Signed-off-by: Rafael J. Wysocki --- drivers/base/power/runtime.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) (limited to 'drivers/base/power/runtime.c') diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 6a58bb77a018..04407d9f76fd 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -66,10 +66,14 @@ static int rpm_suspend(struct device *dev, int rpmflags); */ void update_pm_runtime_accounting(struct device *dev) { - u64 now = ktime_get_mono_fast_ns(); - u64 last = dev->power.accounting_timestamp; - u64 delta; + u64 now, last, delta; + if (dev->power.disable_depth > 0) + return; + + last = dev->power.accounting_timestamp; + + now = ktime_get_mono_fast_ns(); dev->power.accounting_timestamp = now; /* @@ -82,9 +86,6 @@ void update_pm_runtime_accounting(struct device *dev) delta = now - last; - if (dev->power.disable_depth > 0) - return; - if (dev->power.runtime_status == RPM_SUSPENDED) dev->power.suspended_time += delta; else @@ -1298,6 +1299,9 @@ void __pm_runtime_disable(struct device *dev, bool check_resume) pm_runtime_put_noidle(dev); } + /* Update time accounting before disabling PM-runtime. */ + update_pm_runtime_accounting(dev); + if (!dev->power.disable_depth++) __pm_runtime_barrier(dev); @@ -1521,7 +1525,6 @@ void pm_runtime_init(struct device *dev) dev->power.request_pending = false; dev->power.request = RPM_REQ_NONE; dev->power.deferred_resume = false; - dev->power.accounting_timestamp = 0; INIT_WORK(&dev->power.work, pm_runtime_work); dev->power.timer_expires = 0; -- cgit v1.2.3