Messages in this thread | | | Subject | Re: [RFC PATCH v1 00/11] Create fast idle path for short idle periods | From | "Li, Aubrey" <> | Date | Mon, 10 Jul 2017 21:59:41 +0800 |
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On 2017/7/10 16:46, Peter Zijlstra wrote: > On Mon, Jul 10, 2017 at 09:38:30AM +0800, Aubrey Li wrote: >> We measured 3%~5% improvemnt in disk IO workload, and 8%~20% improvement in >> network workload. > > Argh, what a mess :/ > > So how much of the gain is simply due to skipping NOHZ?
netperf reports 6~7% improvement due to skipping NOHZ, but still have 2~3% improvement due to excluding RCU idle enter/exit, c-state selection and other deferrable items. Also a shallow HW c-state is used in the idle loop, which means faster HW sleep enter and exit.
> Mike used to carry a patch that would throttle NOHZ. And that is a _far_ small > and simpler patch to do. > Can you please point me to the link of Mike's patch?
Thanks, -Aubrey
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