From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: PV guest timings Date: Wed, 27 Nov 2013 09:46:35 +0100 Message-ID: <1385541995.15201.197.camel@Solace> References: Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============5809251732361524834==" Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Simon Martin Cc: Roland Heusser , Sisu Xi , Andrew Cooper , Joshua Whitehead , "xen-devel@lists.xen.org" , Drek Darkover , Keir Fraser , Nate Studer List-Id: xen-devel@lists.xenproject.org --===============5809251732361524834== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-LgumgyNo5KufUEHEfpSr" --=-LgumgyNo5KufUEHEfpSr Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On mer, 2013-11-27 at 02:32 +0000, Simon Martin wrote: > =20 > > On mar, 2013-11-26 at 15:38 +0000, Simon Martin wrote:=20 > > =20 > > =20 > > > As an additional comment. I decided to filter out the samples > > > with=20 > > > negative latency. This seems to happen 100 times a second, i.e. > > > the 10=20 > > > ms Hypervisor timer event.=20 > > > =20 > > Again, what's "negative latency" ?=20 > > Latency is the time between the deadline and the handler being called. > Ok, that's a reasonable definition of latency. However, if you don't mind another question, 'deadline' here is basically the deadline of the periodic instance x-1, and you expect a timer firing at that time in order to activate instance x? Or is that a proper deadline (and the above is just called period) and you want to have some handler running when it's missed? > Negative latency means the handler was called before the next > deadline. > =20 Oh, wow... I see. So you're saying that you have timers firing early than their expiry time? Is that expected? Why is that happening? :-O Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-LgumgyNo5KufUEHEfpSr Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.15 (GNU/Linux) iEYEABECAAYFAlKVsWsACgkQk4XaBE3IOsS3JQCgjcGg2qie5GgDWnuZnj5PPnST C+sAoIRmwLDxHpoPk8Xns6x48i0vd2VB =Vuij -----END PGP SIGNATURE----- --=-LgumgyNo5KufUEHEfpSr-- --===============5809251732361524834== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel --===============5809251732361524834==--