From: "David S. Ahern" <daahern@cisco.com>
To: Ulrich Obergfell <uobergfe@redhat.com>
Cc: Anthony Liguori <anthony@codemonkey.ws>,
kvm@vger.kernel.org, glommer@redhat.com, zamsden@redhat.com,
avi@redhat.com, mtosatti@redhat.com
Subject: Re: [RFC 0/4] KVM in-kernel PM Timer implementation
Date: Tue, 14 Dec 2010 11:00:59 -0700 [thread overview]
Message-ID: <4D07B0DB.7010701@cisco.com> (raw)
In-Reply-To: <4D078D5A.9060804@codemonkey.ws>
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
next prev parent reply other threads:[~2010-12-14 18:01 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <344060531.680691292328457867.JavaMail.root@zmail07.collab.prod.int.phx2.redhat.com>
2010-12-14 12:09 ` [RFC 0/4] KVM in-kernel PM Timer implementation Ulrich Obergfell
2010-12-14 13:34 ` Avi Kivity
2010-12-14 13:40 ` Glauber Costa
2010-12-14 13:49 ` Avi Kivity
2010-12-14 13:52 ` Gleb Natapov
2010-12-14 15:32 ` Anthony Liguori
2010-12-14 15:38 ` Avi Kivity
2010-12-14 16:04 ` Anthony Liguori
2010-12-15 9:33 ` Avi Kivity
2010-12-14 15:29 ` Anthony Liguori
2010-12-14 18:00 ` David S. Ahern [this message]
2010-12-14 19:49 ` Anthony Liguori
2010-12-14 19:54 ` David S. Ahern
2010-12-14 21:46 ` Anthony Liguori
2010-12-14 23:59 ` David S. Ahern
[not found] <953393305.700721292337871455.JavaMail.root@zmail07.collab.prod.int.phx2.redhat.com>
2010-12-14 14:44 ` Ulrich Obergfell
2010-12-14 15:12 ` Avi Kivity
[not found] <1956121317.795411292413874075.JavaMail.root@zmail07.collab.prod.int.phx2.redhat.com>
2010-12-15 11:53 ` Ulrich Obergfell
2012-02-21 18:10 ` Peter Lieven
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