This patch add the detailed description of 'load_table' debugfs file to show collected CPUs load and the change of CPU frequency. Signed-off-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> Signed-off-by: Myungjoo Ham <myungjoo.ham@xxxxxxxxxxx> --- Changes since v5: - Add description of test case Documentation/cpu-freq/cpufreq-stats.txt | 40 ++++++++++++++++++++++++++++---- 1 file changed, 36 insertions(+), 4 deletions(-) diff --git a/Documentation/cpu-freq/cpufreq-stats.txt b/Documentation/cpu-freq/cpufreq-stats.txt index fc64749..f1d97d03 100644 --- a/Documentation/cpu-freq/cpufreq-stats.txt +++ b/Documentation/cpu-freq/cpufreq-stats.txt @@ -18,10 +18,12 @@ Contents 1. Introduction cpufreq-stats is a driver that provides CPU frequency statistics for each CPU. -These statistics are provided in /sysfs as a bunch of read_only interfaces. This -interface (when configured) will appear in a separate directory under cpufreq -in /sysfs (<sysfs root>/devices/system/cpu/cpuX/cpufreq/stats/) for each CPU. -Various statistics will form read_only files under this directory. +These statistics are provided in /sysfs and /debugfs as a bunch of read_only +interfaces. This interface (when configured) will appear in a separate directory +under cpufreq in below directory list for each CPU. Various statistics will form +read_only files under this directory. +- /sysfs (<sysfs root>/devices/system/cpu/cpuX/cpufreq/stats/) +- /debugfs (<sysfs root>/kernel/debug/cpufreq/cpuX/) This driver is designed to be independent of any particular cpufreq_driver that may be running on your CPU. So, it will work with any cpufreq_driver. @@ -33,6 +35,7 @@ cpufreq stats provides following statistics (explained in detail below). - time_in_state - total_trans - trans_table +- load_table All the statistics will be from the time the stats driver has been inserted to the time when a read of a particular statistic is done. Obviously, stats @@ -95,6 +98,29 @@ contains the actual freq values for each row and column for better readability. 2800000: 0 0 0 2 0 -------------------------------------------------------------------------------- +- load_table +This gives the collected CPUs data which include measured time, old CPU +frequency, new CPU frequency and each CPU load. The cat output will have +"<measured time> <old CPU frequency> <new CPU frequency> <CPUs load> ..." pair +in each line, which will mean the change of CPU frequency according to CPUs load +at <measured time>. + +-------------------------------------------------------------------------------- +- In case that all CPUs share only one voltage/frequency. +<mysystem>:/sys/kernel/debug/cpufreq/cpu0 # cat load_table +Time(ms) Old Freq(Hz) New Freq(Hz) CPU0 CPU1 CPU2 CPU3 +23820 500000 500000 53 86 2 73 +23920 500000 400000 66 40 0 42 +24020 400000 400000 71 71 10 52 +24120 400000 300000 33 27 45 65 +24220 300000 300000 4 37 71 34 +24320 300000 300000 1 85 38 16 +24420 300000 200000 6 41 15 51 +24520 200000 200000 12 62 1 51 +24620 200000 200000 9 51 0 58 +24720 200000 200000 32 32 11 27 +-------------------------------------------------------------------------------- + 3. Configuring cpufreq-stats @@ -104,6 +130,7 @@ Config Main Menu CPU Frequency scaling ---> [*] CPU Frequency scaling <*> CPU frequency translation statistics + (10) Maximum storage size to save CPU load (10-1000) [*] CPU frequency translation statistics details @@ -113,6 +140,11 @@ cpufreq-stats. "CPU frequency translation statistics" (CONFIG_CPU_FREQ_STAT) provides the basic statistics which includes time_in_state and total_trans. +"Maximum storage size to save CPU load (10-1000)" (depends on CONFIG_CPU_FREQ_ +STAT) indicates the total number of load_table data and provides collected data +which include old cpu frequency, new cpu frequency and CPUs load. The user can +determine the storage size of collected CPUs data. The range is from 10 to 1000. + "CPU frequency translation statistics details" (CONFIG_CPU_FREQ_STAT_DETAILS) provides fine grained cpufreq stats by trans_table. The reason for having a separate config option for trans_table is: -- 1.8.0 -- To unsubscribe from this list: send the line "unsubscribe cpufreq" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
