Messages in this thread | | | Date | Tue, 15 Nov 2022 11:26:55 -0600 | Subject | Re: [RFC v2 1/3] PM: Add a sysfs files to represent sleep duration | From | "Limonciello, Mario" <> |
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On 11/15/2022 11:20, Raul Rangel wrote: > > > On Tue, Nov 15, 2022 at 9:35 AM Rafael J. Wysocki <rafael@kernel.org > <mailto:rafael@kernel.org>> wrote: > > On Tue, Nov 15, 2022 at 4:17 PM Limonciello, Mario > <mario.limonciello@amd.com <mailto:mario.limonciello@amd.com>> wrote: > > > > On 11/15/2022 08:45, Rafael J. Wysocki wrote: > > > On Thu, Nov 10, 2022 at 7:49 AM Mario Limonciello > > > <mario.limonciello@amd.com <mailto:mario.limonciello@amd.com>> > wrote: > > >> > > >> Both AMD and Intel SoCs have a concept of reporting whether > the hardware > > >> reached a hardware sleep state over s2idle as well as how much > > >> time was spent in such a state. > > >> > > >> This information is valuable to both chip designers and system > designers > > >> as it helps to identify when there are problems with power > consumption > > >> over an s2idle cycle. > > >> > > >> To make the information discoverable, create a new sysfs file > and a symbol > > >> that drivers from supported manufacturers can use to advertise > this > > >> information. This file will only be exported when the system > supports low > > >> power idle in the ACPI table. > > >> > > >> In order to effectively use this information you will ideally > want to > > >> compare against the total duration of sleep, so export a > second sysfs file > > >> that will show total time. This file will be exported on all > systems and > > >> used both for s2idle and s3. > > > > > > Well, my first question would be how this is related to > > > > > > /sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us > > > > > > > This has a dependency on the platform firmware offering an ACPI LPIT > > table. I don't know how common that is. > > Required for running Windows with Modern Standby AFAICS. > > > As this series started from the needs on ChromeOS I would ask is > that typically populated by coreboot? > > It should be, but I'd need to ask for confirmation. > > > It looks like Intel platforms have support for the LPIT table: > https://source.chromium.org/chromiumos/chromiumos/codesearch/+/main:src/third_party/coreboot/src/soc/intel/common/block/acpi/lpit.c?q=f:LPIT%20f:coreboot&ss=chromiumos <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsource.chromium.org%2Fchromiumos%2Fchromiumos%2Fcodesearch%2F%2B%2Fmain%3Asrc%2Fthird_party%2Fcoreboot%2Fsrc%2Fsoc%2Fintel%2Fcommon%2Fblock%2Facpi%2Flpit.c%3Fq%3Df%3ALPIT%2520f%3Acoreboot%26ss%3Dchromiumos&data=05%7C01%7Cmario.limonciello%40amd.com%7C701602845ad14f37abbb08dac72db514%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C638041296400209575%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=9ig2jlDevXMjzmTUf42WS5Ey3rLd2lDUXjncz3mbyMI%3D&reserved=0> > > For AMD, we had some patches to add _LPIL > https://review.coreboot.org/c/coreboot/+/52381/1 > <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Freview.coreboot.org%2Fc%2Fcoreboot%2F%2B%2F52381%2F1&data=05%7C01%7Cmario.limonciello%40amd.com%7C701602845ad14f37abbb08dac72db514%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C638041296400209575%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=KV6ASbdfNOex%2FZtJYcdItZU1gdjCIXEcP1ExiY0pkf8%3D&reserved=0> > They never got merged though. We could add an LPIT table to coreboot for > AMD platforms if necessary.
_LPI I don't think makes a lot of sense on X86 today, which is why this was sent up: eb087f305919e ("ACPI: processor idle: Check for architectural support for LPI")
As for LPIT - I've never seen LPIT on AMD UEFI systems either. I guess it's an Intel specific table?
> > > I would hope it's the same number that is populated in that file on > > supported systems though. > > Well, which is exactly where I'm going. > > Since there is one sysfs file for exposing this value already and it > is used (for example, by sleepgraph), perhaps the way to go would be > to extend this interface to systems that don't have LPIT instead of > introducing a new one possibly exposing the same value? >
Ah; so since Raul confirmed coreboot on Chrome exports that maybe we just need to add another way to populate that sysfs file for systems without LPIT (IE AMD). I think that's a very good idea; thanks.
I think we still probably want to have a way to get the total suspend time out programmatically though to compare to. So perhaps the other sysfs file I had in the RFC v2 makes sense still.
> > > and > > > > > > /sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us > > > > > > > No relation to this one for what's in the series. > > > > >> Suggested-by: David E Box <david.e.box@intel.com > <mailto:david.e.box@intel.com>> > > >> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com > <mailto:mario.limonciello@amd.com>> > > >> --- > > >> Documentation/ABI/testing/sysfs-power | 17 +++++++++++ > > >> include/linux/suspend.h | 4 +++ > > >> kernel/power/main.c | 42 > +++++++++++++++++++++++++++ > > >> kernel/power/suspend.c | 2 ++ > > >> kernel/time/timekeeping.c | 2 ++ > > >> 5 files changed, 67 insertions(+) > > >> > > >> diff --git a/Documentation/ABI/testing/sysfs-power > b/Documentation/ABI/testing/sysfs-power > > >> index f99d433ff311..5b47cbb4dc9e 100644 > > >> --- a/Documentation/ABI/testing/sysfs-power > > >> +++ b/Documentation/ABI/testing/sysfs-power > > >> @@ -413,6 +413,23 @@ Description: > > >> The /sys/power/suspend_stats/last_failed_step > file contains > > >> the last failed step in the suspend/resume path. > > >> > > >> +What: /sys/power/suspend_stats/last_hw_state_residency > > >> +Date: December 2022 > > >> +Contact: Mario Limonciello <mario.limonciello@amd.com > <mailto:mario.limonciello@amd.com>> > > >> +Description: > > >> + The > /sys/power/suspend_stats/last_hw_state_residency file contains > > >> + the amount of time spent in a hardware sleep > state. > > >> + This attribute is only available if the system > supports > > >> + low power idle. This is measured in microseconds. > > >> + > > >> +What: /sys/power/suspend_stats/last_suspend_total > > >> +Date: December 2022 > > >> +Contact: Mario Limonciello <mario.limonciello@amd.com > <mailto:mario.limonciello@amd.com>> > > >> +Description: > > >> + The > /sys/power/suspend_stats/last_suspend_total file contains > > >> + the total duration of the sleep cycle. > > >> + This is measured in microseconds. > > >> + > > >> What: /sys/power/sync_on_suspend > > >> Date: October 2019 > > >> Contact: Jonas Meurer <jonas@freesources.org > <mailto:jonas@freesources.org>> > > >> diff --git a/include/linux/suspend.h b/include/linux/suspend.h > > >> index cfe19a028918..af343c3f8198 100644 > > >> --- a/include/linux/suspend.h > > >> +++ b/include/linux/suspend.h > > >> @@ -68,6 +68,8 @@ struct suspend_stats { > > >> int last_failed_errno; > > >> int errno[REC_FAILED_NUM]; > > >> int last_failed_step; > > >> + u64 last_hw_state_residency; > > >> + u64 last_suspend_total; > > >> enum suspend_stat_step failed_steps[REC_FAILED_NUM]; > > >> }; > > >> > > >> @@ -489,6 +491,8 @@ void restore_processor_state(void); > > >> extern int register_pm_notifier(struct notifier_block *nb); > > >> extern int unregister_pm_notifier(struct notifier_block *nb); > > >> extern void ksys_sync_helper(void); > > >> +extern void pm_set_hw_state_residency(u64 duration); > > >> +extern void pm_account_suspend_type(const struct timespec64 *t); > > >> > > >> #define pm_notifier(fn, pri) { \ > > >> static struct notifier_block fn##_nb = \ > > >> diff --git a/kernel/power/main.c b/kernel/power/main.c > > >> index 31ec4a9b9d70..11bd658583b0 100644 > > >> --- a/kernel/power/main.c > > >> +++ b/kernel/power/main.c > > >> @@ -6,6 +6,7 @@ > > >> * Copyright (c) 2003 Open Source Development Lab > > >> */ > > >> > > >> +#include <linux/acpi.h> > > >> #include <linux/export.h> > > >> #include <linux/kobject.h> > > >> #include <linux/string.h> > > >> @@ -54,6 +55,19 @@ void unlock_system_sleep(unsigned int flags) > > >> } > > >> EXPORT_SYMBOL_GPL(unlock_system_sleep); > > >> > > >> +void pm_set_hw_state_residency(u64 duration) > > >> +{ > > >> + suspend_stats.last_hw_state_residency = duration; > > >> +} > > >> +EXPORT_SYMBOL_GPL(pm_set_hw_state_residency); > > >> + > > >> +void pm_account_suspend_type(const struct timespec64 *t) > > >> +{ > > >> + suspend_stats.last_suspend_total += (s64)t->tv_sec * > USEC_PER_SEC + > > >> + t->tv_nsec / > NSEC_PER_USEC; > > >> +} > > >> +EXPORT_SYMBOL_GPL(pm_account_suspend_type); > > >> + > > >> void ksys_sync_helper(void) > > >> { > > >> ktime_t start; > > >> @@ -377,6 +391,20 @@ static ssize_t > last_failed_step_show(struct kobject *kobj, > > >> } > > >> static struct kobj_attribute last_failed_step = > __ATTR_RO(last_failed_step); > > >> > > >> +static ssize_t last_hw_state_residency_show(struct kobject *kobj, > > >> + struct kobj_attribute *attr, char *buf) > > >> +{ > > >> + return sprintf(buf, "%llu\n", > suspend_stats.last_hw_state_residency); > > >> +} > > >> +static struct kobj_attribute last_hw_state_residency = > __ATTR_RO(last_hw_state_residency); > > >> + > > >> +static ssize_t last_suspend_total_show(struct kobject *kobj, > > >> + struct kobj_attribute *attr, char *buf) > > >> +{ > > >> + return sprintf(buf, "%llu\n", > suspend_stats.last_suspend_total); > > >> +} > > >> +static struct kobj_attribute last_suspend_total = > __ATTR_RO(last_suspend_total); > > >> + > > >> static struct attribute *suspend_attrs[] = { > > >> &success.attr, > > >> &fail.attr, > > >> @@ -391,12 +419,26 @@ static struct attribute *suspend_attrs[] = { > > >> &last_failed_dev.attr, > > >> &last_failed_errno.attr, > > >> &last_failed_step.attr, > > >> + &last_hw_state_residency.attr, > > >> + &last_suspend_total.attr, > > >> NULL, > > >> }; > > >> > > >> +static umode_t suspend_attr_is_visible(struct kobject *kobj, > struct attribute *attr, int idx) > > >> +{ > > >> + if (attr != &last_hw_state_residency.attr) > > >> + return 0444; > > >> +#ifdef CONFIG_ACPI > > >> + if (acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0) > > >> + return 0444; > > >> +#endif > > >> + return 0; > > >> +} > > >> + > > >> static const struct attribute_group suspend_attr_group = { > > >> .name = "suspend_stats", > > >> .attrs = suspend_attrs, > > >> + .is_visible = suspend_attr_is_visible, > > >> }; > > >> > > >> #ifdef CONFIG_DEBUG_FS > > >> diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c > > >> index fa3bf161d13f..b6c4a3733212 100644 > > >> --- a/kernel/power/suspend.c > > >> +++ b/kernel/power/suspend.c > > >> @@ -423,6 +423,8 @@ static int suspend_enter(suspend_state_t > state, bool *wakeup) > > >> if (suspend_test(TEST_PLATFORM)) > > >> goto Platform_wake; > > >> > > >> + suspend_stats.last_suspend_total = 0; > > >> + > > >> if (state == PM_SUSPEND_TO_IDLE) { > > >> s2idle_loop(); > > >> goto Platform_wake; > > >> diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c > > >> index f72b9f1de178..e1b356787e53 100644 > > >> --- a/kernel/time/timekeeping.c > > >> +++ b/kernel/time/timekeeping.c > > >> @@ -24,6 +24,7 @@ > > >> #include <linux/compiler.h> > > >> #include <linux/audit.h> > > >> #include <linux/random.h> > > >> +#include <linux/suspend.h> > > >> > > >> #include "tick-internal.h" > > >> #include "ntp_internal.h" > > >> @@ -1698,6 +1699,7 @@ static void > __timekeeping_inject_sleeptime(struct timekeeper *tk, > > >> tk_set_wall_to_mono(tk, > timespec64_sub(tk->wall_to_monotonic, *delta)); > > >> tk_update_sleep_time(tk, timespec64_to_ktime(*delta)); > > >> tk_debug_account_sleep_time(delta); > > >> + pm_account_suspend_type(delta); > > >> } > > >> > > >> #if defined(CONFIG_PM_SLEEP) && > defined(CONFIG_RTC_HCTOSYS_DEVICE) > > >> -- > > >> 2.34.1 > > >> > > >
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