RE: [PATCH] cpufreq, intel_pstate, set max_sysfs_pct and min_sysfs_pct on governor switch

From: Prarit Bhargava
Date: Wed Oct 07 2015 - 10:34:32 EST


Doug, please apply and test.

My result is:

\# initial load of driver, set to PERFORMANCE governor by default.

[ 21.406525] intel_pstate_set_policy[1001] min_perf_pct = 100
[ 21.421288] intel_pstate_set_policy[1001] min_perf_pct = 100
[ 21.436038] intel_pstate_set_policy[1001] min_perf_pct = 100
[ 21.450505] intel_pstate_set_policy[1001] min_perf_pct = 100

\# echo 100 > /sys/devices/system/cpu/intel_pstate/min_perf_pct

[ 21.483436] store_min_perf_pct[453] min_sysfs_pct = 100
[ 21.489373] store_min_perf_pct[456] min_perf_pct = 100
[ 21.495203] store_min_perf_pct[459] min_perf_pct = 100
[ 21.501050] store_min_perf_pct[462] min_perf_pct = 100

\# cpupower -c all frequency-set -g powersave

[ 214.187212] intel_pstate_set_policy[1023] min_perf_pct = 100
[ 214.193643] intel_pstate_set_policy[1028] min_perf_pct = 100
[ 214.200205] intel_pstate_set_policy[1020] min_perf_pct = 100
[ 214.206626] intel_pstate_set_policy[1023] min_perf_pct = 100
[ 214.213064] intel_pstate_set_policy[1028] min_perf_pct = 100
[ 214.219601] intel_pstate_set_policy[1020] min_perf_pct = 100
[ 214.226008] intel_pstate_set_policy[1023] min_perf_pct = 100
[ 214.232471] intel_pstate_set_policy[1028] min_perf_pct = 100
[ 214.238990] intel_pstate_set_policy[1020] min_perf_pct = 100
[ 214.245408] intel_pstate_set_policy[1023] min_perf_pct = 100
[ 214.251845] intel_pstate_set_policy[1028] min_perf_pct = 100

\# cat /sys/devices/system/cpu/intel_pstate/*_perf_pct

100
100

Thanks!

P.
---
drivers/cpufreq/intel_pstate.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 3af9dd7..95f6b9f 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -450,9 +450,17 @@ static ssize_t store_min_perf_pct(struct kobject *a, struct attribute *b,
return -EINVAL;

limits.min_sysfs_pct = clamp_t(int, input, 0 , 100);
+ printk("%s[%d] min_sysfs_pct = %d\n", __FUNCTION__, __LINE__,
+ limits.min_sysfs_pct);
limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct);
+ printk("%s[%d] min_perf_pct = %d\n", __FUNCTION__, __LINE__,
+ limits.min_perf_pct);
limits.min_perf_pct = min(limits.max_policy_pct, limits.min_perf_pct);
+ printk("%s[%d] min_perf_pct = %d\n", __FUNCTION__, __LINE__,
+ limits.min_perf_pct);
limits.min_perf_pct = min(limits.max_perf_pct, limits.min_perf_pct);
+ printk("%s[%d] min_perf_pct = %d\n", __FUNCTION__, __LINE__,
+ limits.min_perf_pct);
limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));

if (hwp_active)
@@ -990,6 +998,8 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
policy->max >= policy->cpuinfo.max_freq) {
limits.min_policy_pct = 100;
limits.min_perf_pct = 100;
+ printk("%s[%d] min_perf_pct = %d\n", __FUNCTION__, __LINE__,
+ limits.min_perf_pct);
limits.min_perf = int_tofp(1);
limits.max_policy_pct = 100;
limits.max_perf_pct = 100;
@@ -1007,10 +1017,16 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct);
limits.min_perf_pct = min(limits.max_policy_pct, limits.min_perf_pct);
limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct);
+ printk("%s[%d] min_perf_pct = %d\n", __FUNCTION__, __LINE__,
+ limits.min_perf_pct);
limits.max_perf_pct = max(limits.min_policy_pct, limits.max_perf_pct);
+ printk("%s[%d] min_perf_pct = %d\n", __FUNCTION__, __LINE__,
+ limits.min_perf_pct);

/* Make sure min_perf_pct <= max_perf_pct */
limits.min_perf_pct = min(limits.max_perf_pct, limits.min_perf_pct);
+ printk("%s[%d] min_perf_pct = %d\n", __FUNCTION__, __LINE__,
+ limits.min_perf_pct);

limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
--
1.8.3.1

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