Re: [PATCH 1/2] cpufreq: serialize calls to __cpufreq_governor()

[Prarit Bhargava <prarit@redhat.com>]

On 10/16/2014 06:57 AM, Viresh Kumar wrote:
> On 14 October 2014 17:12, Prarit Bhargava <prarit@redhat.com> wrote:
>> I've been running both my test and Robert's test for about 5 mins.  In Robert's
>> case I don't see any problems ... in my case I do occasionally get a system
>> panic because of the sysfs access race I described in the other thread (cpu 1
>> holds a sysfs file open, while cpu 2 changes the governor ...)
> 
> Can you give me the exact script? I wasn't able to reproduce it.


#!/bin/bash

i=0
while [ True ]; do
        i=$((i+1))
        echo "ondemand" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor &
        echo "performance" > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor &
        echo "ondemand" > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor &
        echo "performance" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor &
        if [ $((i % 100)) = 0 ]; then
                echo $i
        fi
done


P.