Re: [PATCH] 2.6.1 Hyperthread smart "nice" 2

From: Ingo Molnar
Date: Mon Feb 02 2004 - 05:31:36 EST



* Con Kolivas <kernel@xxxxxxxxxxx> wrote:

> What this one does is the following; If there is a "nice" difference
> between tasks running on logical cores of the same cpu, the more
> "nice" one will run a proportion of time equal to the timeslice it
> would have been given relative to the less "nice" task. ie a nice 19
> task running on one core and the nice 0 task running on the other core
> will let the nice 0 task run continuously (102ms is normal timeslice)
> and the nice 19 task will only run for the last 10ms of time the nice
> 0 task is running. This makes for a much more balanced resource
> distribution, gives significant preference to the higher priority
> task, but allows them to benefit from running on both logical cores.

this is a really good rule conceptually - the higher prio task will get
at least as much raw (unshared) physical CPU slice as it would get
without HT.

Ingo
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