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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-10-25 20:00:50 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-10-25 20:00:50 +0200 |
| commit | 8c76163fff18f2149f923e1b3c34d00801668244 (patch) | |
| tree | ad9b4d3f8cd40aac5ebf219710ac8782876e612a /Documentation | |
| parent | Merge tag 'pci-v6.12-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/gi... (diff) | |
| parent | Merge branch 'pm-powercap' (diff) | |
| download | linux-8c76163fff18f2149f923e1b3c34d00801668244.tar.xz linux-8c76163fff18f2149f923e1b3c34d00801668244.zip | |
Merge tag 'pm-6.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fixes from Rafael Wysocki:
"Update cpufreq documentation to match the code after recent changes
(Christian Loehle), fix a units conversion issue in the CPPC cpufreq
driver (liwei), and fix an error check in the dtpm_devfreq power
capping driver (Yuan Can)"
* tag 'pm-6.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpufreq: CPPC: fix perf_to_khz/khz_to_perf conversion exception
powercap: dtpm_devfreq: Fix error check against dev_pm_qos_add_request()
cpufreq: docs: Reflect latency changes in docs
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/admin-guide/pm/cpufreq.rst | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/Documentation/admin-guide/pm/cpufreq.rst b/Documentation/admin-guide/pm/cpufreq.rst index fe1be4ad88cb..a21369eba034 100644 --- a/Documentation/admin-guide/pm/cpufreq.rst +++ b/Documentation/admin-guide/pm/cpufreq.rst @@ -425,8 +425,8 @@ This governor exposes only one tunable: ``rate_limit_us`` Minimum time (in microseconds) that has to pass between two consecutive - runs of governor computations (default: 1000 times the scaling driver's - transition latency). + runs of governor computations (default: 1.5 times the scaling driver's + transition latency or the maximum 2ms). The purpose of this tunable is to reduce the scheduler context overhead of the governor which might be excessive without it. @@ -474,17 +474,17 @@ This governor exposes the following tunables: This is how often the governor's worker routine should run, in microseconds. - Typically, it is set to values of the order of 10000 (10 ms). Its - default value is equal to the value of ``cpuinfo_transition_latency`` - for each policy this governor is attached to (but since the unit here - is greater by 1000, this means that the time represented by - ``sampling_rate`` is 1000 times greater than the transition latency by - default). + Typically, it is set to values of the order of 2000 (2 ms). Its + default value is to add a 50% breathing room + to ``cpuinfo_transition_latency`` on each policy this governor is + attached to. The minimum is typically the length of two scheduler + ticks. If this tunable is per-policy, the following shell command sets the time - represented by it to be 750 times as high as the transition latency:: + represented by it to be 1.5 times as high as the transition latency + (the default):: - # echo `$(($(cat cpuinfo_transition_latency) * 750 / 1000)) > ondemand/sampling_rate + # echo `$(($(cat cpuinfo_transition_latency) * 3 / 2)) > ondemand/sampling_rate ``up_threshold`` If the estimated CPU load is above this value (in percent), the governor |