Messages in this thread | | | Date | Fri, 6 Mar 2020 13:33:40 -0500 | From | Phil Auld <> | Subject | Re: [RFC PATCH v4 00/19] Core scheduling v4 |
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On Fri, Mar 06, 2020 at 10:06:16AM -0800 Tim Chen wrote: > On 3/5/20 6:41 PM, Aaron Lu wrote: > > >>> So this appeared to me like a question of: is it desirable to protect/enhance > >>> high weight task performance in the presence of core scheduling? > >> > >> This sounds to me a policy VS mechanism question. Do you have any idea > >> how to spread high weight task among the cores with coresched enabled? > > > > Yes I would like to get us on the same page of the expected behaviour > > before jumping to the implementation details. As for how to achieve > > that: I'm thinking about to make core wide load balanced and then high > > weight task shall spread on different cores. This isn't just about load > > balance, the initial task placement will also need to be considered of > > course if the high weight task only runs a small period. > > > > I am wondering why this is not happening: > > When the low weight task group has exceeded its cfs allocation during a cfs period, the task group > should be throttled. In that case, the CPU cores that the low > weight task group occupies will become idle, and allow load balance from the > overloaded CPUs for the high weight task group to migrate over. >
cpu.shares is not quota. I think it will only get throttled if it has and exceeds quota. Shares are supposed to be used to help weight contention without providing a hard limit.
Cheers, Phil
> Tim >
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