ULE patch, call for testers

Eitan Adler lists at eitanadler.com
Fri Nov 2 20:36:48 UTC 2012

On 2 November 2012 14:26, Jeff Roberson <jroberson at jroberson.net> wrote:
> I have a small patch to the ULE scheduler that makes a fairly large change
> to the way timeshare threads are handled.
> http://people.freebsd.org/~jeff/schedslice.diff
> Previously ULE used a fixed slice size for all timeshare threads.  Now it
> scales the slice size down based on load.  This should reduce latency for
> timeshare threads as load increases.  It is important to note that this does
> not impact interactive threads.  But when a thread transitions to
> interactive from timeshare it should see some improvement.  This happens
> when something like Xorg chews up a lot of CPU.
> If anyone has perf tests they'd like to run please report back.  I have done
> a handful of validation.

does it make sense to make these sysctls?

+#define	SCHED_SLICE_DEFAULT_DIVISOR	10	/* 100 ms. */
+#define	SCHED_SLICE_MIN_DIVISOR		4	/* DEFAULT/MIN = 25 ms. */

Eitan Adler

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