From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: xentrace, xenalyze Date: Wed, 24 Feb 2016 15:51:59 +0100 Message-ID: <1456325519.17312.70.camel@citrix.com> References: Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1668821392078791619==" 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: Paul Sujkov , xen-devel@lists.xen.org Cc: george.dunlap@citrix.com List-Id: xen-devel@lists.xenproject.org --===============1668821392078791619== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-BUjHPkEMW5tq5X4sz4Ku" --=-BUjHPkEMW5tq5X4sz4Ku Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, 2016-02-24 at 15:21 +0200, Paul Sujkov wrote: > Hi, >=20 Hi, > I'm from GlobalLogic team that uses Xen as a base for an automative > platform. Got few questions regarding Xen tracing and it seems that > existing documentation is rather limited. >=20 It is... > At the previous Xen Hackathon I was talking about shared (mediated > pass-through) GPU concept for ARM; it's working well, but still has > performance issues, and some of them seem to be correlated to other > Xen subsystems, but it's not obvious why so (e.g. turning off pv real > time clock driver gives us a significant boost in overall graphics > performance). So, I'm looking for two things here actually: >=20 Great to hear you're (still) working on this. I'm looking forward to see the results! :-D > 1. to understand how can I use xenalyze to find bottlenecks in the > system at the moment > This is hard to tell (at least with such a broad scope). xentrace supports quite a bit of events, but enabling all of them may may not be what you want. For one, it would produce traces that are so big and complex to analyze, that it would be very hard to make sense out of them. I usually enable a subset of them (one or more "classes") and try to figure out if I see the problem in the resulting trace. If yes, I try with a narrower subset. If not, I try with either a broader or a different one. > 2. to add VGPU scheduler traces to Xen trace subsystem, xenbaked, > xentrace and xenalyze >=20 I've never used xenbaked. I've only used xentrace_format and xenalyze. I don't know if xenbaked still works/can still be useful. > Some insights into the second question can be found in RTDS scheduler > patches (it adds a few of it's own trace events and uses generic > scheduler tracing); however, it uses already functioning scheduler > tracing subsystem which is VCPU specific and is not suitable for > VGPU, and there are no visible patches to xenalyze to parse these > traces out. >=20 Have a look at this series: =C2=A0http://lists.xenproject.org/archives/html/xen-devel/2016-02/msg02233.= html And I've got another one that I'll send out asap (and I can Cc you). There are for sure some examples of adding trace points in Xen, and adding support for them in xentrace_format and xenalyze. Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-BUjHPkEMW5tq5X4sz4Ku 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 iEYEABECAAYFAlbNw48ACgkQk4XaBE3IOsRX/QCgklE5qxR/Z8DSqJ2f6bZTLnWJ HWoAni/2o7jio9d3PQ8zW0ptDS2E2QBm =sqy5 -----END PGP SIGNATURE----- --=-BUjHPkEMW5tq5X4sz4Ku-- --===============1668821392078791619== 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 --===============1668821392078791619==--