Re: Phoronix CFS vs BFS bencharks

From: Mike Galbraith
Date: Mon Sep 14 2009 - 11:32:53 EST


On Mon, 2009-09-14 at 16:27 +0200, Marcin Letyns wrote:
> Hello,
>
> Disabling NEW_FAIR_SLEEPERS makes a lot of difference here in the
> Apache benchmark:
>
> 2.6.30.6-bfs: 7311.05
>
> 2.6.30.6-cfs-fair_sl_disabled: 8249.17
>
> 2.6.30.6-cfs-fair_sl_enabled: 4894.99

Wow.

Some loads like wakeup preemption (mysql+oltp), and some hate it. This
load appears to REALLY hate it (as does volanomark, but that thing is
extremely overloaded). How many threads does that benchmark run
concurrently?

In any case, it's currently disabled in tip. Time will tell which
benchmarks gain, and which lose. With it disabled, anything light loses
when competing with hog(s). There _are_ one heck of a lot of hogs out
there though, so maybe it _should_ be disabled by default. Dunno.

-Mike

--
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/