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| author | Gary E. Miller <gem@rellim.com> | 2016-06-30 20:36:49 -0700 |
|---|---|---|
| committer | Gary E. Miller <gem@rellim.com> | 2016-06-30 20:36:49 -0700 |
| commit | 7c22c78550440f4111712fce01c022fcdc2441d4 (patch) | |
| tree | 4003927cf4fd6acd76aef8b88d06bac0f3b919f6 /www | |
| parent | bd6b7235a5bd0874b34d25d94dc8ae5a25dc5c28 (diff) | |
| download | gpsd-7c22c78550440f4111712fce01c022fcdc2441d4.tar.gz | |
Add a mention to use only the performance governor.
Having the CPU change frequencies and idle states adds errors to
the timekeeping.
Diffstat (limited to 'www')
| -rw-r--r-- | www/gpsd-time-service-howto.txt | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/www/gpsd-time-service-howto.txt b/www/gpsd-time-service-howto.txt index 3b5452c2..5cf84ca1 100644 --- a/www/gpsd-time-service-howto.txt +++ b/www/gpsd-time-service-howto.txt @@ -1104,7 +1104,7 @@ improved local and remote offsets. Normally enabling power saving features is a good thing: it saves you power. But when your CPU changes power saving modes (cstates for Intel CPUs) the impact on PPS timing is noticeable. For some reason the NO_HZ kernel -mode has a similar bad effecct on timekeeping. +mode has a similar bad effect on timekeeping. To improve your timekeeping, turn off both features on Intel CPUs by adding this to your boot command line: @@ -1119,6 +1119,10 @@ For ARM, be sure NO_HZ is off: nohz=off ----------------------------------------------------------------------------- +You will also need to select the 'performance' CPU governor to keep ypur +CPU set to the maximum speed for continuous usage. How you see and set +your governor will be distribution specific. The easiest way it to +recompile your kernel to only provide the performance governor. == NTP tuning and performance details == |