2019-05-27 13:17:38

by Harry Pan

Subject: [PATCH] platform/x86: intel_pmc_core: transform Pkg C-state residency from TSC ticks into microseconds

Refer to the Intel SDM Vol.4, the package C-state residency counters
of modern IA micro-architecture are all ticking in TSC frequency,
hence we can apply simple math to transform the ticks into microseconds.
i.e.,
residency (ms) = count / tsc_khz
residency (us) = count / tsc_khz * 1000

This also aligns to other sysfs debug entries of residency counter in
the same metric in microseconds, benefits reading and scripting.

Signed-off-by: Harry Pan <[email protected]>

---

drivers/platform/x86/intel_pmc_core.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/x86/intel_pmc_core.c b/drivers/platform/x86/intel_pmc_core.c
index f2c621b55f49..20e0843ebfb4 100644
--- a/drivers/platform/x86/intel_pmc_core.c
+++ b/drivers/platform/x86/intel_pmc_core.c
@@ -24,6 +24,7 @@
#include <asm/cpu_device_id.h>
#include <asm/intel-family.h>
#include <asm/msr.h>
+#include <asm/tsc.h>

#include "intel_pmc_core.h"

@@ -726,7 +727,6 @@ static int pmc_core_ltr_show(struct seq_file *s, void *unused)
return 0;
}
DEFINE_SHOW_ATTRIBUTE(pmc_core_ltr);
-
static int pmc_core_pkgc_show(struct seq_file *s, void *unused)
{
struct pmc_dev *pmcdev = s->private;
@@ -738,8 +738,8 @@ static int pmc_core_pkgc_show(struct seq_file *s, void *unused)
if (rdmsrl_safe(map[index].bit_mask, &pcstate_count))
continue;

- seq_printf(s, "%-8s : 0x%llx\n", map[index].name,
- pcstate_count);
+ seq_printf(s, "%-8s : %llu\n", map[index].name,
+ pcstate_count * 1000 / tsc_khz);
}

return 0;
--
2.20.1

2019-05-28 02:57:33

by Harry Pan

Subject: [PATCH] platform/x86: intel_pmc_core: transform Pkg C-state residency from TSC ticks into microseconds

Refer to the Intel SDM Vol.4, the package C-state residency counters
of modern IA micro-architecture are all ticking in TSC frequency,
hence we can apply simple math to transform the ticks into microseconds.
i.e.,
residency (ms) = count / tsc_khz
residency (us) = count / tsc_khz * 1000

This also aligns to other sysfs debug entries of residency counter in
the same metric in microseconds, benefits reading and scripting.

v2: restore the accidentally deleted newline, no function change.

Signed-off-by: Harry Pan <[email protected]>

---

drivers/platform/x86/intel_pmc_core.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/intel_pmc_core.c b/drivers/platform/x86/intel_pmc_core.c
index f2c621b55f49..c78918a7e731 100644
--- a/drivers/platform/x86/intel_pmc_core.c
+++ b/drivers/platform/x86/intel_pmc_core.c
@@ -24,6 +24,7 @@
#include <asm/cpu_device_id.h>
#include <asm/intel-family.h>
#include <asm/msr.h>
+#include <asm/tsc.h>

#include "intel_pmc_core.h"

@@ -738,8 +739,8 @@ static int pmc_core_pkgc_show(struct seq_file *s, void *unused)
if (rdmsrl_safe(map[index].bit_mask, &pcstate_count))
continue;

- seq_printf(s, "%-8s : 0x%llx\n", map[index].name,
- pcstate_count);
+ seq_printf(s, "%-8s : %llu\n", map[index].name,
+ pcstate_count * 1000 / tsc_khz);
}

return 0;
--
2.20.1

2019-05-28 03:01:19

by Harry Pan

Subject: [PATCH v2] platform/x86: intel_pmc_core: transform Pkg C-state residency from TSC ticks into microseconds

Refer to the Intel SDM Vol.4, the package C-state residency counters
of modern IA micro-architecture are all ticking in TSC frequency,
hence we can apply simple math to transform the ticks into microseconds.
i.e.,
residency (ms) = count / tsc_khz
residency (us) = count / tsc_khz * 1000

This also aligns to other sysfs debug entries of residency counter in
the same metric in microseconds, benefits reading and scripting.

v2: restore the accidentally deleted newline, no function change.

Signed-off-by: Harry Pan <[email protected]>

---

drivers/platform/x86/intel_pmc_core.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/intel_pmc_core.c b/drivers/platform/x86/intel_pmc_core.c
index f2c621b55f49..c78918a7e731 100644
--- a/drivers/platform/x86/intel_pmc_core.c
+++ b/drivers/platform/x86/intel_pmc_core.c
@@ -24,6 +24,7 @@
#include <asm/cpu_device_id.h>
#include <asm/intel-family.h>
#include <asm/msr.h>
+#include <asm/tsc.h>

#include "intel_pmc_core.h"

@@ -738,8 +739,8 @@ static int pmc_core_pkgc_show(struct seq_file *s, void *unused)
if (rdmsrl_safe(map[index].bit_mask, &pcstate_count))
continue;

- seq_printf(s, "%-8s : 0x%llx\n", map[index].name,
- pcstate_count);
+ seq_printf(s, "%-8s : %llu\n", map[index].name,
+ pcstate_count * 1000 / tsc_khz);
}

return 0;
--
2.20.1

2019-06-19 08:28:43

by Harry Pan

Subject: [PATCH v3] platform/x86: intel_pmc_core: transform Pkg C-state residency from TSC ticks into microseconds

Refer to the Intel SDM Vol.4, the package C-state residency counters
of modern IA micro-architecture are all ticking in TSC frequency,
hence we can apply simple math to transform the ticks into microseconds.
i.e.,
residency (ms) = count / tsc_khz
residency (us) = count / tsc_khz * 1000

This also aligns to other sysfs debug entries of residency counter in
the same metric in microseconds, benefits reading and scripting.

v2: restore the accidentally deleted newline, no function change.
v3: apply kernel do_div() macro to calculate division

Signed-off-by: Harry Pan <[email protected]>

---

drivers/platform/x86/intel_pmc_core.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/x86/intel_pmc_core.c b/drivers/platform/x86/intel_pmc_core.c
index f2c621b55f49..ab798efacc85 100644
--- a/drivers/platform/x86/intel_pmc_core.c
+++ b/drivers/platform/x86/intel_pmc_core.c
@@ -24,6 +24,7 @@
#include <asm/cpu_device_id.h>
#include <asm/intel-family.h>
#include <asm/msr.h>
+#include <asm/tsc.h>

#include "intel_pmc_core.h"

@@ -738,7 +739,9 @@ static int pmc_core_pkgc_show(struct seq_file *s, void *unused)
if (rdmsrl_safe(map[index].bit_mask, &pcstate_count))
continue;

- seq_printf(s, "%-8s : 0x%llx\n", map[index].name,
+ pcstate_count *= 1000;
+ do_div(pcstate_count, tsc_khz);
+ seq_printf(s, "%-8s : %llu\n", map[index].name,
pcstate_count);
}

--
2.20.1

2019-06-29 13:24:49

by Andy Shevchenko

Subject: Re: [PATCH v3] platform/x86: intel_pmc_core: transform Pkg C-state residency from TSC ticks into microseconds

On Wed, Jun 19, 2019 at 11:29 AM Harry Pan <[email protected]> wrote:
>
> Refer to the Intel SDM Vol.4, the package C-state residency counters
> of modern IA micro-architecture are all ticking in TSC frequency,
> hence we can apply simple math to transform the ticks into microseconds.
> i.e.,
> residency (ms) = count / tsc_khz
> residency (us) = count / tsc_khz * 1000
>
> This also aligns to other sysfs debug entries of residency counter in
> the same metric in microseconds, benefits reading and scripting.
>
> v2: restore the accidentally deleted newline, no function change.
> v3: apply kernel do_div() macro to calculate division
>
> Signed-off-by: Harry Pan <[email protected]>
>

Pushed to my review and testing queue, thanks!

> ---
>
> drivers/platform/x86/intel_pmc_core.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/platform/x86/intel_pmc_core.c b/drivers/platform/x86/intel_pmc_core.c
> index f2c621b55f49..ab798efacc85 100644
> --- a/drivers/platform/x86/intel_pmc_core.c
> +++ b/drivers/platform/x86/intel_pmc_core.c
> @@ -24,6 +24,7 @@
> #include <asm/cpu_device_id.h>
> #include <asm/intel-family.h>
> #include <asm/msr.h>
> +#include <asm/tsc.h>
>
> #include "intel_pmc_core.h"
>
> @@ -738,7 +739,9 @@ static int pmc_core_pkgc_show(struct seq_file *s, void *unused)
> if (rdmsrl_safe(map[index].bit_mask, &pcstate_count))
> continue;
>
> - seq_printf(s, "%-8s : 0x%llx\n", map[index].name,
> + pcstate_count *= 1000;
> + do_div(pcstate_count, tsc_khz);
> + seq_printf(s, "%-8s : %llu\n", map[index].name,
> pcstate_count);
> }
>
> --
> 2.20.1
>


--
With Best Regards,
Andy Shevchenko