Bug 111241 - one need root credentials to read cpuinfo_cur_freq content
Summary: one need root credentials to read cpuinfo_cur_freq content
Status: CLOSED DUPLICATE of bug 65611
Alias: None
Product: Power Management
Classification: Unclassified
Component: cpufreq (show other bugs)
Hardware: All Linux
: P1 normal
Assignee: linux-pm@vger.kernel.org
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2016-01-24 09:16 UTC by flux242
Modified: 2016-05-16 21:47 UTC (History)
2 users (show)

See Also:
Kernel Version: 4.4.0-994-generic
Subsystem:
Regression: No
Bisected commit-id:

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Description flux242 2016-01-24 09:16:21 UTC 
could somebody explain why do I need root credentials to read cpuinfo_cur_freq file? Why other files in the same directory have 444 and not 400 as the cpuinfo_cur_freq? What so special about the current cpu freq readings?  

$ lso /sys/devices/system/cpu/cpu?/cpufreq/cpuinfo*
 400 -r-------- 1 root 4.0K Jan 24 09:30 /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq
 444 -r--r--r-- 1 root 4.0K Jan 24 09:37 /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq
 444 -r--r--r-- 1 root 4.0K Jan 24 09:37 /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq
 444 -r--r--r-- 1 root 4.0K Jan 24 09:37 /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_transition_latency
 400 -r-------- 1 root 4.0K Jan 24 09:53 /sys/devices/system/cpu/cpu1/cpufreq/cpuinfo_cur_freq
 444 -r--r--r-- 1 root 4.0K Jan 24 09:53 /sys/devices/system/cpu/cpu1/cpufreq/cpuinfo_max_freq
 444 -r--r--r-- 1 root 4.0K Jan 24 09:53 /sys/devices/system/cpu/cpu1/cpufreq/cpuinfo_min_freq
 444 -r--r--r-- 1 root 4.0K Jan 24 09:53 /sys/devices/system/cpu/cpu1/cpufreq/cpuinfo_transition_latency
Comment 1 Doug Smythies 2016-01-24 16:33:12 UTC 
This one is a duplicate of bug 65611, and the rational is partially therein and particularly in the links within comment 6.
Comment 2 flux242 2016-01-24 17:09:14 UTC 
well, the problem is 12 years people are still confused why it is this way. Which makes me to believe that something is wrong with the design. Anyway, as far as I can read from scaling_cur_freq I'm fine.
Comment 3 Len Brown 2016-05-16 21:47:45 UTC 

*** This bug has been marked as a duplicate of bug 65611 ***
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