This is a note to let you know that I've just added the patch titled
intel_pstate: Take core C0 time into account for core busy calculation
to the 3.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
intel_pstate-take-core-c0-time-into-account-for-core-busy-calculation.patch
and it can be found in the queue-3.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From fcb6a15c2e7e76d493e6f91ea889ab40e1c643a4 Mon Sep 17 00:00:00 2001
From: Dirk Brandewie <dirk.j.brandewie@xxxxxxxxx>
Date: Mon, 3 Feb 2014 08:55:31 -0800
Subject: intel_pstate: Take core C0 time into account for core busy calculation
From: Dirk Brandewie <dirk.j.brandewie@xxxxxxxxx>
commit fcb6a15c2e7e76d493e6f91ea889ab40e1c643a4 upstream.
Take non-idle time into account when calculating core busy time.
This ensures that intel_pstate will notice a decrease in load.
References: https://bugzilla.kernel.org/show_bug.cgi?id=66581
Cc: 3.10+ <stable@xxxxxxxxxxxxxxx> # 3.10+
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@xxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/cpufreq/intel_pstate.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -51,6 +51,7 @@ struct sample {
int32_t core_pct_busy;
u64 aperf;
u64 mperf;
+ unsigned long long tsc;
int freq;
};
@@ -86,6 +87,7 @@ struct cpudata {
u64 prev_aperf;
u64 prev_mperf;
+ unsigned long long prev_tsc;
int sample_ptr;
struct sample samples[SAMPLE_COUNT];
};
@@ -436,11 +438,17 @@ static inline void intel_pstate_calc_bus
struct sample *sample)
{
u64 core_pct;
- core_pct = div64_u64(int_tofp(sample->aperf * 100),
- sample->mperf);
- sample->freq = fp_toint(cpu->pstate.max_pstate * core_pct * 1000);
+ u64 c0_pct;
- sample->core_pct_busy = core_pct;
+ core_pct = div64_u64(sample->aperf * 100, sample->mperf);
+
+ c0_pct = div64_u64(sample->mperf * 100, sample->tsc);
+ sample->freq = fp_toint(
+ mul_fp(int_tofp(cpu->pstate.max_pstate),
+ int_tofp(core_pct * 1000)));
+
+ sample->core_pct_busy = mul_fp(int_tofp(core_pct),
+ div_fp(int_tofp(c0_pct + 1), int_tofp(100)));
}
static inline void intel_pstate_sample(struct cpudata *cpu)
Patches currently in stable-queue which might be from dirk.j.brandewie@xxxxxxxxx are
queue-3.12/intel_pstate-take-core-c0-time-into-account-for-core-busy-calculation.patch
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