Re: [RFC 0/4] KVM in-kernel PM Timer implementation

David S. Ahern
2010-12-14T18:01:01Z

On 12/14/10 08:29, Anthony Liguori wrote:

>> I recently used to investigate the performance benefit. In a Linux
>> guest, I was running a program that calls gettimeofday() 'n' times
>> in a loop (the PM Timer register is read during each call). With
>> in-kernel PM Timer, I observed a significant reduction of program
>> execution time.
>>
>
> I've played with this in the past. Can you post real numbers,
> preferably, with a real work load?

2 years ago I posted relative comparisons of the time sources for older
RHEL guests:
http://www.mail-archive.com/kvm@vger.kernel.org/msg07231.html

What's the relative speed of the in-kernel pmtimer compared to the PIT?

David