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.c...@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.p...@samsung.com>
Signed-off-by: Myungjoo Ham <myungjoo....@samsung.com>
---
Documentation/cpu-freq/cpufreq-stats.txt | 39 ++++++++++++++++++++++++++++----
1 file changed, 35 insertions(+), 4 deletions(-)
diff --git a/Documentation/cpu-freq/cpufreq-stats.txt
b/Documentation/cpu-freq/cpufreq-stats.txt
index fc64749..8c2e4f2 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 +98,28 @@ 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>.
+
+--------------------------------------------------------------------------------
+<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 +129,7 @@ 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 +139,11 @@ 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
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