RE: [PATCH][rfc] intel_pstate: Fix user input of min/max to legal policy region
Hi ,Rafael > -Original Message- > From: Rafael J. Wysocki [mailto:r...@rjwysocki.net] > Sent: Tuesday, September 08, 2015 5:47 AM > To: Chen, Yu C; kris...@linux.intel.com > Cc: viresh.ku...@linaro.org; linux...@vger.kernel.org; linux- > ker...@vger.kernel.org; Zhang, Rui; l...@kernel.org > Subject: Re: [PATCH][rfc] intel_pstate: Fix user input of min/max to legal > policy region > > On Wednesday, August 12, 2015 11:49:19 AM Chen Yu wrote: > > In current code, if system is using performance policy, user can > > modify the max_perf_pct to any values lower than 100: > > > > $ grep . /sys/devices/system/cpu/intel_pstate/m*_perf_pct > > /sys/devices/system/cpu/intel_pstate/max_perf_pct:100 > > /sys/devices/system/cpu/intel_pstate/min_perf_pct:100 > > > > $ echo 80 > /sys/devices/system/cpu/intel_pstate/max_perf_pct > > > > $ grep . /sys/devices/system/cpu/intel_pstate/m*_perf_pct > > /sys/devices/system/cpu/intel_pstate/max_perf_pct:80 > > /sys/devices/system/cpu/intel_pstate/min_perf_pct:100 > > > > the max_perf_pct above is lower than min_perf_pct, which is not > > reasonable. > > > > This patch solves this problem by clamping min_perf_pct and > > max_perf_pct to be strictly inside [min_policy_pct,max_policy_pct]. > > > > Signed-off-by: Chen Yu > > Looks reasonable to me. > > Kristen, any objections? > Thanks for your reply! According to suggestion from Seiichi, will re-send a V2 version patch, to make some update. Best Regards, Yu
Re: [PATCH][rfc] intel_pstate: Fix user input of min/max to legal policy region
On Wednesday, August 12, 2015 11:49:19 AM Chen Yu wrote: > In current code, if system is using performance policy, user can > modify the max_perf_pct to any values lower than 100: > > $ grep . /sys/devices/system/cpu/intel_pstate/m*_perf_pct > /sys/devices/system/cpu/intel_pstate/max_perf_pct:100 > /sys/devices/system/cpu/intel_pstate/min_perf_pct:100 > > $ echo 80 > /sys/devices/system/cpu/intel_pstate/max_perf_pct > > $ grep . /sys/devices/system/cpu/intel_pstate/m*_perf_pct > /sys/devices/system/cpu/intel_pstate/max_perf_pct:80 > /sys/devices/system/cpu/intel_pstate/min_perf_pct:100 > > the max_perf_pct above is lower than min_perf_pct, which > is not reasonable. > > This patch solves this problem by clamping min_perf_pct and max_perf_pct > to be strictly inside [min_policy_pct,max_policy_pct]. > > Signed-off-by: Chen Yu Looks reasonable to me. Kristen, any objections? > --- > drivers/cpufreq/intel_pstate.c | 10 +++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c > index fcb929e..3702c5a 100644 > --- a/drivers/cpufreq/intel_pstate.c > +++ b/drivers/cpufreq/intel_pstate.c > @@ -423,6 +423,7 @@ static ssize_t store_max_perf_pct(struct kobject *a, > struct attribute *b, > > limits.max_sysfs_pct = clamp_t(int, input, 0 , 100); > limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct); > + limits.max_perf_pct = max(limits.min_policy_pct, limits.max_perf_pct); > limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100)); > > if (hwp_active) > @@ -442,6 +443,7 @@ static ssize_t store_min_perf_pct(struct kobject *a, > struct attribute *b, > > limits.min_sysfs_pct = clamp_t(int, input, 0 , 100); > 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.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100)); > > if (hwp_active) > @@ -985,12 +987,14 @@ static int intel_pstate_set_policy(struct > cpufreq_policy *policy) > > limits.min_policy_pct = (policy->min * 100) / policy->cpuinfo.max_freq; > limits.min_policy_pct = clamp_t(int, limits.min_policy_pct, 0 , 100); > - limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct); > - limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100)); > - > limits.max_policy_pct = (policy->max * 100) / policy->cpuinfo.max_freq; > limits.max_policy_pct = clamp_t(int, limits.max_policy_pct, 0 , 100); > + > + 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.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100)); > limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct); > + limits.max_perf_pct = max(limits.min_policy_pct, limits.max_perf_pct); > limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100)); > > if (hwp_active) > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH][rfc] intel_pstate: Fix user input of min/max to legal policy region
In current code, if system is using performance policy, user can modify the max_perf_pct to any values lower than 100: $ grep . /sys/devices/system/cpu/intel_pstate/m*_perf_pct /sys/devices/system/cpu/intel_pstate/max_perf_pct:100 /sys/devices/system/cpu/intel_pstate/min_perf_pct:100 $ echo 80 > /sys/devices/system/cpu/intel_pstate/max_perf_pct $ grep . /sys/devices/system/cpu/intel_pstate/m*_perf_pct /sys/devices/system/cpu/intel_pstate/max_perf_pct:80 /sys/devices/system/cpu/intel_pstate/min_perf_pct:100 the max_perf_pct above is lower than min_perf_pct, which is not reasonable. This patch solves this problem by clamping min_perf_pct and max_perf_pct to be strictly inside [min_policy_pct,max_policy_pct]. Signed-off-by: Chen Yu --- drivers/cpufreq/intel_pstate.c | 10 +++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index fcb929e..3702c5a 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -423,6 +423,7 @@ static ssize_t store_max_perf_pct(struct kobject *a, struct attribute *b, limits.max_sysfs_pct = clamp_t(int, input, 0 , 100); limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct); + limits.max_perf_pct = max(limits.min_policy_pct, limits.max_perf_pct); limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100)); if (hwp_active) @@ -442,6 +443,7 @@ static ssize_t store_min_perf_pct(struct kobject *a, struct attribute *b, limits.min_sysfs_pct = clamp_t(int, input, 0 , 100); 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.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100)); if (hwp_active) @@ -985,12 +987,14 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy) limits.min_policy_pct = (policy->min * 100) / policy->cpuinfo.max_freq; limits.min_policy_pct = clamp_t(int, limits.min_policy_pct, 0 , 100); - limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct); - limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100)); - limits.max_policy_pct = (policy->max * 100) / policy->cpuinfo.max_freq; limits.max_policy_pct = clamp_t(int, limits.max_policy_pct, 0 , 100); + + 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.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100)); limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct); + limits.max_perf_pct = max(limits.min_policy_pct, limits.max_perf_pct); limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100)); if (hwp_active) -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
