Re: [RFC PATCH 0/4] Gang scheduling in CFS

[Srivatsa Vaddagiri]

* Avi Kivity <avi@xxxxxxxxxx> [2012-01-04 16:41:58]:

> > Here are some observation related to Baseline-only(8vm case)
> >
> >               | ple_gap=128 | ple_gap=64 | ple_gap=256 | ple_window=2048
> > --------------+-------------+------------+-------------+----------------
> > EbzyRecords/s |    2247.50  |    2132.75 |    2086.25  |      1835.62
> > PauseExits    | 7928154.00  | 6696342.00 | 7365999.00  |  50319582.00
> >
> > With ple_window = 2048, PauseExits is more than 6times the default case
> 
> So it looks like the default is optimal, at least wrt the cases you
> tested and your test workload.

The default case still lags considerably behind the results we are seeing with
gang scheduling. One more interesting data point would be to see how
many PLE exits we are seeing when the vcpu is spinning in
flush_tlb_others_ipi(). Is there any easy way to determine that?

- vatsa

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/