Messages in this thread | | | Date | Wed, 9 Sep 2009 08:13:08 +0200 | From | Ingo Molnar <> | Subject | Re: BFS vs. mainline scheduler benchmarks and measurements |
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* Jens Axboe <jens.axboe@oracle.com> wrote:
> On Tue, Sep 08 2009, Peter Zijlstra wrote: > > On Tue, 2009-09-08 at 11:13 +0200, Jens Axboe wrote: > > > And here's a newer version. > > > > I tinkered a bit with your proglet and finally found the > > problem. > > > > You used a single pipe per child, this means the loop in > > run_child() would consume what it just wrote out until it got > > force preempted by the parent which would also get woken. > > > > This results in the child spinning a while (its full quota) and > > only reporting the last timestamp to the parent. > > Oh doh, that's not well thought out. Well it was a quick hack :-) > Thanks for the fixup, now it's at least usable to some degree.
What kind of latencies does it report on your box?
Our vanilla scheduler default latency targets are:
single-core: 20 msecs dual-core: 40 msecs quad-core: 60 msecs opto-core: 80 msecs
You can enable CONFIG_SCHED_DEBUG=y and set it directly as well via /proc/sys/kernel/sched_latency_ns:
echo 10000000 > /proc/sys/kernel/sched_latency_ns
Ingo
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