Messages in this thread |  | | Date | Thu, 8 Nov 2001 17:33:58 +0100 (CET) | From | Ingo Molnar <> | Subject | RE: [patch] scheduler cache affinity improvement for 2.4 kernels |
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On Thu, 8 Nov 2001, M. Edward Borasky wrote:
> I can think of some circumstances where one would want the *opposite* > of this patch. Consider a "time-sharing" system running both > CPU-intensive "batch" tasks and "interactive" tasks. There is going to > be a tradeoff between efficiency / throughput of the batch tasks and > the response times of interactive ones. [...]
this mechanizm is already part of the scheduler and is not affected by my patch. Interactive tasks get their '->counter' value increased gradually via the recalculate code in the scheduler, which after some time gives them effective priority above that of CPU-intensive processes.
To see this mechanizm working, just boot into the stock kernel or try a kernel with the patch applied, start a few CPU-intensive processes, eg. a couple of subshells doing an infinite loop:
while N=1; do N=1; done & while N=1; do N=1; done & while N=1; do N=1; done & while N=1; do N=1; done &
and see how the interactive shell is still responding instantaneously in such a mixed workload, despite having the same static priority as the subshells.
Ingo
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