Re: [PATCH 5/5] intel_pstate: delete scheduler hook in HWP mode

[Len Brown]

On Fri, Jun 16, 2017 at 8:09 PM, Rafael J. Wysocki  wrote:
> On Wednesday, June 07, 2017 07:39:16 PM Len Brown wrote:
>> From: Len Brown 
>>
>> The cpufreqa/scaling_cur_freq sysfs attribute is now provided by
>> the x86 cpufreq core on all modern x86 systems, including
>> all systems supported by the intel_pstate driver.
>
> Not sure what you mean by "x86 cpufreq core"?

I refer to code that builds if (CONFIG_X86 && CONFIG_CPU_FREQ)

Since it was enough to provoke a comment form you, how about this wording?:

The cpufreq/scaling_cur_freq sysfs attribute is now provided by
shared x86 cpufreq code on modern x86 systems, including
all systems supported by the intel_pstate driver.

> Besides, I'd reorder this change with respect to patch [4/5] as this
> eliminates the hook entirely and then the "performance"-related change
> would only affect non-HWP.

I don't actually see a problem with either order,
but i'll send the refresh with the order you suggest.

thanks,
Len Brown, Intel Open Source Technology Center

Re: [PATCH 5/5] intel_pstate: delete scheduler hook in HWP mode

[Len Brown]

On Fri, Jun 16, 2017 at 8:09 PM, Rafael J. Wysocki  wrote:
> On Wednesday, June 07, 2017 07:39:16 PM Len Brown wrote:
>> From: Len Brown 
>>
>> The cpufreqa/scaling_cur_freq sysfs attribute is now provided by
>> the x86 cpufreq core on all modern x86 systems, including
>> all systems supported by the intel_pstate driver.
>
> Not sure what you mean by "x86 cpufreq core"?

I refer to code that builds if (CONFIG_X86 && CONFIG_CPU_FREQ)

Since it was enough to provoke a comment form you, how about this wording?:

The cpufreq/scaling_cur_freq sysfs attribute is now provided by
shared x86 cpufreq code on modern x86 systems, including
all systems supported by the intel_pstate driver.

> Besides, I'd reorder this change with respect to patch [4/5] as this
> eliminates the hook entirely and then the "performance"-related change
> would only affect non-HWP.

I don't actually see a problem with either order,
but i'll send the refresh with the order you suggest.

thanks,
Len Brown, Intel Open Source Technology Center

Re: [PATCH 5/5] intel_pstate: delete scheduler hook in HWP mode

[Rafael J. Wysocki]

On Wednesday, June 07, 2017 07:39:16 PM Len Brown wrote:
> From: Len Brown 
> 
> The cpufreqa/scaling_cur_freq sysfs attribute is now provided by
> the x86 cpufreq core on all modern x86 systems, including
> all systems supported by the intel_pstate driver.

Not sure what you mean by "x86 cpufreq core"?

Besides, I'd reorder this change with respect to patch [4/5] as this
eliminates the hook entirely and then the "performance"-related change
would only affect non-HWP.

Thanks,
Rafael

Re: [PATCH 5/5] intel_pstate: delete scheduler hook in HWP mode

[Rafael J. Wysocki]

On Wednesday, June 07, 2017 07:39:16 PM Len Brown wrote:
> From: Len Brown 
> 
> The cpufreqa/scaling_cur_freq sysfs attribute is now provided by
> the x86 cpufreq core on all modern x86 systems, including
> all systems supported by the intel_pstate driver.

Not sure what you mean by "x86 cpufreq core"?

Besides, I'd reorder this change with respect to patch [4/5] as this
eliminates the hook entirely and then the "performance"-related change
would only affect non-HWP.

Thanks,
Rafael

[PATCH 5/5] intel_pstate: delete scheduler hook in HWP mode

[Len Brown]

From: Len Brown 

The cpufreqa/scaling_cur_freq sysfs attribute is now provided by
the x86 cpufreq core on all modern x86 systems, including
all systems supported by the intel_pstate driver.

In HWP mode, maintaining that value was the sole purpose of
the scheduler hook, intel_pstate_update_util_hwp(),
so it can now be removed.

Signed-off-by: Len Brown 
---
 drivers/cpufreq/intel_pstate.c | 14 +++---
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 0ff3a4b..718732b 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -1726,16 +1726,6 @@ static void intel_pstate_adjust_pstate(struct cpudata 
*cpu, int target_pstate)
fp_toint(cpu->iowait_boost * 100));
 }
 
-static void intel_pstate_update_util_hwp(struct update_util_data *data,
-u64 time, unsigned int flags)
-{
-   struct cpudata *cpu = container_of(data, struct cpudata, update_util);
-   u64 delta_ns = time - cpu->sample.time;
-
-   if ((s64)delta_ns >= INTEL_PSTATE_HWP_SAMPLING_INTERVAL)
-   intel_pstate_sample(cpu, time);
-}
-
 static void intel_pstate_update_util_pid(struct update_util_data *data,
 u64 time, unsigned int flags)
 {
@@ -1920,6 +1910,9 @@ static void intel_pstate_set_update_util_hook(unsigned 
int cpu_num)
 {
struct cpudata *cpu = all_cpu_data[cpu_num];
 
+   if (hwp_active)
+   return;
+
if (cpu->update_util_set)
return;
 
@@ -2543,7 +2536,6 @@ static int __init intel_pstate_init(void)
} else {
hwp_active++;
intel_pstate.attr = hwp_cpufreq_attrs;
-   pstate_funcs.update_util = intel_pstate_update_util_hwp;
goto hwp_cpu_matched;
}
} else {
-- 
2.7.4

[PATCH 5/5] intel_pstate: delete scheduler hook in HWP mode

[Len Brown]

From: Len Brown 

The cpufreqa/scaling_cur_freq sysfs attribute is now provided by
the x86 cpufreq core on all modern x86 systems, including
all systems supported by the intel_pstate driver.

In HWP mode, maintaining that value was the sole purpose of
the scheduler hook, intel_pstate_update_util_hwp(),
so it can now be removed.

Signed-off-by: Len Brown 
---
 drivers/cpufreq/intel_pstate.c | 14 +++---
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 0ff3a4b..718732b 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -1726,16 +1726,6 @@ static void intel_pstate_adjust_pstate(struct cpudata 
*cpu, int target_pstate)
fp_toint(cpu->iowait_boost * 100));
 }
 
-static void intel_pstate_update_util_hwp(struct update_util_data *data,
-u64 time, unsigned int flags)
-{
-   struct cpudata *cpu = container_of(data, struct cpudata, update_util);
-   u64 delta_ns = time - cpu->sample.time;
-
-   if ((s64)delta_ns >= INTEL_PSTATE_HWP_SAMPLING_INTERVAL)
-   intel_pstate_sample(cpu, time);
-}
-
 static void intel_pstate_update_util_pid(struct update_util_data *data,
 u64 time, unsigned int flags)
 {
@@ -1920,6 +1910,9 @@ static void intel_pstate_set_update_util_hook(unsigned 
int cpu_num)
 {
struct cpudata *cpu = all_cpu_data[cpu_num];
 
+   if (hwp_active)
+   return;
+
if (cpu->update_util_set)
return;
 
@@ -2543,7 +2536,6 @@ static int __init intel_pstate_init(void)
} else {
hwp_active++;
intel_pstate.attr = hwp_cpufreq_attrs;
-   pstate_funcs.update_util = intel_pstate_update_util_hwp;
goto hwp_cpu_matched;
}
} else {
-- 
2.7.4