ULE patch, call for testers
Jeff Roberson
jroberson at jroberson.net
Fri Nov 2 21:00:56 UTC 2012
On Fri, 2 Nov 2012, Eitan Adler wrote:
> 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. */
>
DEFAULT_DIVISOR is indirectly through the sysctls that modify the slice.
The min divisor could be. I will consider adding that.
Thanks,
Jeff
>
> --
> Eitan Adler
>
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