[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] How to increase timer resolution?

On 14/9/08 18:53, "Robert Kaiser" <kaiser@xxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:

> On Sunday 14 September 2008 18:41:05 Keir Fraser wrote:
>> The set_timer() infrastructure is not actually tick-based. With an APIC
>> you'll get timer accuracy of around 100us (this figure because we service
>> timer handlers up to 100us before the deadline specified to set_timer(),
>> just to avoid multiple timer interrupts for close-together events). Without
>> this extra fudge factor you'd get accuracy down to microsecond resolution.
> Aha, the TIME_SLOP constant, right? So is it safe to simply reduce this
> to -say- 10us in  order to get a 20us resolution? Will check his out as soon
> as I have a suitable test machine.

Yes, frankly you can set it to zero for your purposes.

 -- Keir

Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.