* [PATCH] cpufreq: Select schedutil when using big.LITTLE
@ 2020-04-02 8:02 ` Linus Walleij
0 siblings, 0 replies; 8+ messages in thread
From: Linus Walleij @ 2020-04-02 8:02 UTC (permalink / raw)
To: Rafael J . Wysocki, Viresh Kumar
Cc: linux-pm, linux-arm-kernel, Arnd Bergmann, Russell King,
Linus Walleij, Vincent Guittot, Sudeep Holla
When we are using a system with big.LITTLE HMP
configuration, we need to use EAS to schedule the
system.
As can be seen from kernel/sched/topology.c:
"EAS can be used on a root domain if it meets all the following conditions:
1. an Energy Model (EM) is available;
2. the SD_ASYM_CPUCAPACITY flag is set in the sched_domain hierarchy.
3. no SMT is detected.
4. the EM complexity is low enough to keep scheduling overheads low;
5. schedutil is driving the frequency of all CPUs of the rd;"
This means that at the very least, schedutil needs to be
available as a scheduling policy for EAS to work on these
systems. Make this explicit by defaulting to the schedutil
governor if BIG_LITTLE is selected.
Currently users of the TC2 board (like me) has to figure these
dependencies out themselves and it is not helpful.
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
drivers/cpufreq/Kconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index bff5295016ae..873aefd96cf2 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -36,6 +36,7 @@ config CPU_FREQ_STAT
choice
prompt "Default CPUFreq governor"
+ default CPU_FREQ_DEFAULT_GOV_SCHEDUTIL if BIG_LITTLE
default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ
default CPU_FREQ_DEFAULT_GOV_PERFORMANCE
help
--
2.25.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH] cpufreq: Select schedutil when using big.LITTLE
@ 2020-04-02 8:02 ` Linus Walleij
0 siblings, 0 replies; 8+ messages in thread
From: Linus Walleij @ 2020-04-02 8:02 UTC (permalink / raw)
To: Rafael J . Wysocki, Viresh Kumar
Cc: Arnd Bergmann, linux-pm, Linus Walleij, Russell King,
Sudeep Holla, linux-arm-kernel
When we are using a system with big.LITTLE HMP
configuration, we need to use EAS to schedule the
system.
As can be seen from kernel/sched/topology.c:
"EAS can be used on a root domain if it meets all the following conditions:
1. an Energy Model (EM) is available;
2. the SD_ASYM_CPUCAPACITY flag is set in the sched_domain hierarchy.
3. no SMT is detected.
4. the EM complexity is low enough to keep scheduling overheads low;
5. schedutil is driving the frequency of all CPUs of the rd;"
This means that at the very least, schedutil needs to be
available as a scheduling policy for EAS to work on these
systems. Make this explicit by defaulting to the schedutil
governor if BIG_LITTLE is selected.
Currently users of the TC2 board (like me) has to figure these
dependencies out themselves and it is not helpful.
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
drivers/cpufreq/Kconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index bff5295016ae..873aefd96cf2 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -36,6 +36,7 @@ config CPU_FREQ_STAT
choice
prompt "Default CPUFreq governor"
+ default CPU_FREQ_DEFAULT_GOV_SCHEDUTIL if BIG_LITTLE
default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ
default CPU_FREQ_DEFAULT_GOV_PERFORMANCE
help
--
2.25.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH] cpufreq: Select schedutil when using big.LITTLE
2020-04-02 8:02 ` Linus Walleij
@ 2020-04-02 9:14 ` Sudeep Holla
-1 siblings, 0 replies; 8+ messages in thread
From: Sudeep Holla @ 2020-04-02 9:14 UTC (permalink / raw)
To: Linus Walleij
Cc: Rafael J . Wysocki, Viresh Kumar, linux-pm, linux-arm-kernel,
Arnd Bergmann, Russell King, Sudeep Holla, Vincent Guittot
On Thu, Apr 02, 2020 at 10:02:39AM +0200, Linus Walleij wrote:
> When we are using a system with big.LITTLE HMP
> configuration, we need to use EAS to schedule the
> system.
>
> As can be seen from kernel/sched/topology.c:
>
> "EAS can be used on a root domain if it meets all the following conditions:
> 1. an Energy Model (EM) is available;
> 2. the SD_ASYM_CPUCAPACITY flag is set in the sched_domain hierarchy.
> 3. no SMT is detected.
> 4. the EM complexity is low enough to keep scheduling overheads low;
> 5. schedutil is driving the frequency of all CPUs of the rd;"
>
> This means that at the very least, schedutil needs to be
> available as a scheduling policy for EAS to work on these
> systems. Make this explicit by defaulting to the schedutil
> governor if BIG_LITTLE is selected.
>
> Currently users of the TC2 board (like me) has to figure these
> dependencies out themselves and it is not helpful.
>
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Cc: Vincent Guittot <vincent.guittot@linaro.org>
> Cc: Viresh Kumar <viresh.kumar@linaro.org>
> Cc: Sudeep Holla <sudeep.holla@arm.com>
Good to see another user of TC2 ;)
FWIW:
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
--
Regards,
Sudeep
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] cpufreq: Select schedutil when using big.LITTLE
@ 2020-04-02 9:14 ` Sudeep Holla
0 siblings, 0 replies; 8+ messages in thread
From: Sudeep Holla @ 2020-04-02 9:14 UTC (permalink / raw)
To: Linus Walleij
Cc: Arnd Bergmann, linux-pm, Viresh Kumar, Rafael J . Wysocki,
Russell King, Sudeep Holla, linux-arm-kernel
On Thu, Apr 02, 2020 at 10:02:39AM +0200, Linus Walleij wrote:
> When we are using a system with big.LITTLE HMP
> configuration, we need to use EAS to schedule the
> system.
>
> As can be seen from kernel/sched/topology.c:
>
> "EAS can be used on a root domain if it meets all the following conditions:
> 1. an Energy Model (EM) is available;
> 2. the SD_ASYM_CPUCAPACITY flag is set in the sched_domain hierarchy.
> 3. no SMT is detected.
> 4. the EM complexity is low enough to keep scheduling overheads low;
> 5. schedutil is driving the frequency of all CPUs of the rd;"
>
> This means that at the very least, schedutil needs to be
> available as a scheduling policy for EAS to work on these
> systems. Make this explicit by defaulting to the schedutil
> governor if BIG_LITTLE is selected.
>
> Currently users of the TC2 board (like me) has to figure these
> dependencies out themselves and it is not helpful.
>
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Cc: Vincent Guittot <vincent.guittot@linaro.org>
> Cc: Viresh Kumar <viresh.kumar@linaro.org>
> Cc: Sudeep Holla <sudeep.holla@arm.com>
Good to see another user of TC2 ;)
FWIW:
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
--
Regards,
Sudeep
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] cpufreq: Select schedutil when using big.LITTLE
2020-04-02 9:14 ` Sudeep Holla
@ 2020-04-02 9:44 ` Rafael J. Wysocki
-1 siblings, 0 replies; 8+ messages in thread
From: Rafael J. Wysocki @ 2020-04-02 9:44 UTC (permalink / raw)
To: Sudeep Holla, Linus Walleij
Cc: Rafael J . Wysocki, Viresh Kumar, Linux PM, Linux ARM,
Arnd Bergmann, Russell King, Vincent Guittot
On Thu, Apr 2, 2020 at 11:15 AM Sudeep Holla <sudeep.holla@arm.com> wrote:
>
> On Thu, Apr 02, 2020 at 10:02:39AM +0200, Linus Walleij wrote:
> > When we are using a system with big.LITTLE HMP
> > configuration, we need to use EAS to schedule the
> > system.
> >
> > As can be seen from kernel/sched/topology.c:
> >
> > "EAS can be used on a root domain if it meets all the following conditions:
> > 1. an Energy Model (EM) is available;
> > 2. the SD_ASYM_CPUCAPACITY flag is set in the sched_domain hierarchy.
> > 3. no SMT is detected.
> > 4. the EM complexity is low enough to keep scheduling overheads low;
> > 5. schedutil is driving the frequency of all CPUs of the rd;"
> >
> > This means that at the very least, schedutil needs to be
> > available as a scheduling policy for EAS to work on these
> > systems. Make this explicit by defaulting to the schedutil
> > governor if BIG_LITTLE is selected.
> >
> > Currently users of the TC2 board (like me) has to figure these
> > dependencies out themselves and it is not helpful.
> >
> > Suggested-by: Arnd Bergmann <arnd@arndb.de>
> > Cc: Vincent Guittot <vincent.guittot@linaro.org>
> > Cc: Viresh Kumar <viresh.kumar@linaro.org>
> > Cc: Sudeep Holla <sudeep.holla@arm.com>
>
> Good to see another user of TC2 ;)
>
> FWIW:
> Acked-by: Sudeep Holla <sudeep.holla@arm.com>
This slightly clashes with
https://patchwork.kernel.org/patch/11463531/, so I'm going to queue up
them both.
Thanks!
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] cpufreq: Select schedutil when using big.LITTLE
@ 2020-04-02 9:44 ` Rafael J. Wysocki
0 siblings, 0 replies; 8+ messages in thread
From: Rafael J. Wysocki @ 2020-04-02 9:44 UTC (permalink / raw)
To: Sudeep Holla, Linus Walleij
Cc: Arnd Bergmann, Linux PM, Viresh Kumar, Rafael J . Wysocki,
Russell King, Linux ARM
On Thu, Apr 2, 2020 at 11:15 AM Sudeep Holla <sudeep.holla@arm.com> wrote:
>
> On Thu, Apr 02, 2020 at 10:02:39AM +0200, Linus Walleij wrote:
> > When we are using a system with big.LITTLE HMP
> > configuration, we need to use EAS to schedule the
> > system.
> >
> > As can be seen from kernel/sched/topology.c:
> >
> > "EAS can be used on a root domain if it meets all the following conditions:
> > 1. an Energy Model (EM) is available;
> > 2. the SD_ASYM_CPUCAPACITY flag is set in the sched_domain hierarchy.
> > 3. no SMT is detected.
> > 4. the EM complexity is low enough to keep scheduling overheads low;
> > 5. schedutil is driving the frequency of all CPUs of the rd;"
> >
> > This means that at the very least, schedutil needs to be
> > available as a scheduling policy for EAS to work on these
> > systems. Make this explicit by defaulting to the schedutil
> > governor if BIG_LITTLE is selected.
> >
> > Currently users of the TC2 board (like me) has to figure these
> > dependencies out themselves and it is not helpful.
> >
> > Suggested-by: Arnd Bergmann <arnd@arndb.de>
> > Cc: Vincent Guittot <vincent.guittot@linaro.org>
> > Cc: Viresh Kumar <viresh.kumar@linaro.org>
> > Cc: Sudeep Holla <sudeep.holla@arm.com>
>
> Good to see another user of TC2 ;)
>
> FWIW:
> Acked-by: Sudeep Holla <sudeep.holla@arm.com>
This slightly clashes with
https://patchwork.kernel.org/patch/11463531/, so I'm going to queue up
them both.
Thanks!
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] cpufreq: Select schedutil when using big.LITTLE
2020-04-02 8:02 ` Linus Walleij
@ 2020-04-03 5:48 ` Viresh Kumar
-1 siblings, 0 replies; 8+ messages in thread
From: Viresh Kumar @ 2020-04-03 5:48 UTC (permalink / raw)
To: Linus Walleij
Cc: Rafael J . Wysocki, linux-pm, linux-arm-kernel, Arnd Bergmann,
Russell King, Vincent Guittot, Sudeep Holla
On 02-04-20, 10:02, Linus Walleij wrote:
> When we are using a system with big.LITTLE HMP
> configuration, we need to use EAS to schedule the
> system.
>
> As can be seen from kernel/sched/topology.c:
>
> "EAS can be used on a root domain if it meets all the following conditions:
> 1. an Energy Model (EM) is available;
> 2. the SD_ASYM_CPUCAPACITY flag is set in the sched_domain hierarchy.
> 3. no SMT is detected.
> 4. the EM complexity is low enough to keep scheduling overheads low;
> 5. schedutil is driving the frequency of all CPUs of the rd;"
>
> This means that at the very least, schedutil needs to be
> available as a scheduling policy for EAS to work on these
> systems. Make this explicit by defaulting to the schedutil
> governor if BIG_LITTLE is selected.
>
> Currently users of the TC2 board (like me) has to figure these
> dependencies out themselves and it is not helpful.
>
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Cc: Vincent Guittot <vincent.guittot@linaro.org>
> Cc: Viresh Kumar <viresh.kumar@linaro.org>
> Cc: Sudeep Holla <sudeep.holla@arm.com>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> drivers/cpufreq/Kconfig | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
> index bff5295016ae..873aefd96cf2 100644
> --- a/drivers/cpufreq/Kconfig
> +++ b/drivers/cpufreq/Kconfig
> @@ -36,6 +36,7 @@ config CPU_FREQ_STAT
>
> choice
> prompt "Default CPUFreq governor"
> + default CPU_FREQ_DEFAULT_GOV_SCHEDUTIL if BIG_LITTLE
> default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ
> default CPU_FREQ_DEFAULT_GOV_PERFORMANCE
> help
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
--
viresh
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] cpufreq: Select schedutil when using big.LITTLE
@ 2020-04-03 5:48 ` Viresh Kumar
0 siblings, 0 replies; 8+ messages in thread
From: Viresh Kumar @ 2020-04-03 5:48 UTC (permalink / raw)
To: Linus Walleij
Cc: Arnd Bergmann, linux-pm, Rafael J . Wysocki, Russell King,
Sudeep Holla, linux-arm-kernel
On 02-04-20, 10:02, Linus Walleij wrote:
> When we are using a system with big.LITTLE HMP
> configuration, we need to use EAS to schedule the
> system.
>
> As can be seen from kernel/sched/topology.c:
>
> "EAS can be used on a root domain if it meets all the following conditions:
> 1. an Energy Model (EM) is available;
> 2. the SD_ASYM_CPUCAPACITY flag is set in the sched_domain hierarchy.
> 3. no SMT is detected.
> 4. the EM complexity is low enough to keep scheduling overheads low;
> 5. schedutil is driving the frequency of all CPUs of the rd;"
>
> This means that at the very least, schedutil needs to be
> available as a scheduling policy for EAS to work on these
> systems. Make this explicit by defaulting to the schedutil
> governor if BIG_LITTLE is selected.
>
> Currently users of the TC2 board (like me) has to figure these
> dependencies out themselves and it is not helpful.
>
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Cc: Vincent Guittot <vincent.guittot@linaro.org>
> Cc: Viresh Kumar <viresh.kumar@linaro.org>
> Cc: Sudeep Holla <sudeep.holla@arm.com>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> drivers/cpufreq/Kconfig | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
> index bff5295016ae..873aefd96cf2 100644
> --- a/drivers/cpufreq/Kconfig
> +++ b/drivers/cpufreq/Kconfig
> @@ -36,6 +36,7 @@ config CPU_FREQ_STAT
>
> choice
> prompt "Default CPUFreq governor"
> + default CPU_FREQ_DEFAULT_GOV_SCHEDUTIL if BIG_LITTLE
> default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ
> default CPU_FREQ_DEFAULT_GOV_PERFORMANCE
> help
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
--
viresh
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2020-04-03 5:49 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2020-04-02 8:02 [PATCH] cpufreq: Select schedutil when using big.LITTLE Linus Walleij
2020-04-02 8:02 ` Linus Walleij
2020-04-02 9:14 ` Sudeep Holla
2020-04-02 9:14 ` Sudeep Holla
2020-04-02 9:44 ` Rafael J. Wysocki
2020-04-02 9:44 ` Rafael J. Wysocki
2020-04-03 5:48 ` Viresh Kumar
2020-04-03 5:48 ` Viresh Kumar
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