Messages in this thread | | | Subject | Re: [PATCH] [v2] intel_pstate: Fix user input of min/max to legal policy region | From | Seiichi Ikarashi <> | Date | Wed, 9 Sep 2015 20:12:01 +0900 |
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Hi, Yu
On 2015-09-09 19:27, Chen Yu wrote: > In current code, max_perf_pct might be smaller than min_perf_pct > by improper user input: > > $ 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 > > Fix this problem by 2 steps: > 1.Normalize the user input to [min_policy, max_policy]. > 2.Make sure max_perf_pct>=min_perf_pct, suggested by Seiichi Ikarashi. > > Signed-off-by: Chen Yu <yu.c.chen@intel.com> > --- > v2: > - Add logic to ensure max_perf_pct>=min_perf_pct. > --- > drivers/cpufreq/intel_pstate.c | 17 ++++++++++++++--- > 1 file changed, 14 insertions(+), 3 deletions(-) > > diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c > index fcb929e..a0b935f 100644 > --- a/drivers/cpufreq/intel_pstate.c > +++ b/drivers/cpufreq/intel_pstate.c > @@ -423,6 +423,8 @@ 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_pct = max(limits.min_perf_pct, limits.max_perf_pct); > limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100)); > > if (hwp_active) > @@ -442,6 +444,8 @@ 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_pct = min(limits.max_perf_pct, limits.min_perf_pct); > limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100)); > > if (hwp_active) > @@ -985,12 +989,19 @@ 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); > + > + /* Normalize user input to [min_policy_pct, max_policy_pct] */ > + 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); > + limits.max_perf_pct = max(limits.min_policy_pct, limits.max_perf_pct); > + > + /* Make sure min_perf_pct <= max_perf_pct */ > + limits.min_perf_pct = min(limits.max_perf_pct, limits.min_perf_pct);
You chose max_perf_pct prior to min_perf_pct here. I agree.
> + > + 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)); > > if (hwp_active) >
I think this patch is what it should be. Good job.
Regards, Seiichi
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