On Tue, Nov 15, 2022 at 6:27 PM Limonciello, Mario <mario.limonciello@xxxxxxx> wrote: > > On 11/15/2022 11:20, Raul Rangel wrote: > > > > > > On Tue, Nov 15, 2022 at 9:35 AM Rafael J. Wysocki <rafael@xxxxxxxxxx > > <mailto:rafael@xxxxxxxxxx>> wrote: > > > > On Tue, Nov 15, 2022 at 4:17 PM Limonciello, Mario > > <mario.limonciello@xxxxxxx <mailto:mario.limonciello@xxxxxxx>> wrote: > > > > > > On 11/15/2022 08:45, Rafael J. Wysocki wrote: > > > > On Thu, Nov 10, 2022 at 7:49 AM Mario Limonciello > > > > <mario.limonciello@xxxxxxx <mailto:mario.limonciello@xxxxxxx>> > > 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") Well, LPI has nothing to do with LPIT. [I guess this could not be even more confusing, but that's what you get in the world of 4-letter TLAs.] > As for LPIT - I've never seen LPIT on AMD UEFI systems either. I guess > it's an Intel specific table? It used to be. The spec is UEFI-hosted now. > > > > > 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. Well there are trace points to get that (sleepgraph uses these too), see Documentation/trace/events-power.rst (and you can git grep for "machine_suspend" to find where this comes from). I guess there could be a sysfs file in addition to them, but I'm not sure if the extra overhead would be worth the benefit. > > > > 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@xxxxxxxxx > > <mailto:david.e.box@xxxxxxxxx>> > > > >> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx > > <mailto:mario.limonciello@xxxxxxx>> > > > >> --- > > > >> 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@xxxxxxx > > <mailto:mario.limonciello@xxxxxxx>> > > > >> +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@xxxxxxx > > <mailto:mario.limonciello@xxxxxxx>> > > > >> +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@xxxxxxxxxxxxxxx > > <mailto:jonas@xxxxxxxxxxxxxxx>> > > > >> 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 > > > >> > > > > > >
