From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [PATCH V3] libxl: Increase device model startup timeout to 1min. Date: Tue, 14 Jul 2015 11:25:41 +0200 Message-ID: <1436865941.13522.68.camel@citrix.com> References: <21915.58620.948343.728555@mariner.uk.xensource.com> <1436281753-19534-1-git-send-email-anthony.perard@citrix.com> <21915.60619.555732.214104@mariner.uk.xensource.com> <1436283671.25646.254.camel@citrix.com> <55A4C593020000780009077E@mail.emea.novell.com> <1436860520.7019.140.camel@citrix.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============2951087429650506424==" Return-path: In-Reply-To: <1436860520.7019.140.camel@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell Cc: Wei Liu , Stefano Stabellini , Ian Jackson , xen-devel@lists.xen.org, Jan Beulich , Anthony PERARD List-Id: xen-devel@lists.xenproject.org --===============2951087429650506424== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-2F1gdjK9XdB8IVoH2b61" --=-2F1gdjK9XdB8IVoH2b61 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2015-07-14 at 08:55 +0100, Ian Campbell wrote: > On Tue, 2015-07-14 at 07:17 +0100, Jan Beulich wrote: > > >>> On 07.07.15 at 17:41, wrote: > > > On Tue, 2015-07-07 at 16:14 +0100, Ian Jackson wrote: > > >> Anthony PERARD writes ("[PATCH V3] libxl: Increase device model star= tup=20 > > > timeout to 1min."): > > >> > On a busy host, QEMU may take more than 10s to load and start. > > >> >=20 > > >> > This is likely due to a bug in Linux where the I/O subsystem somet= ime > > >> > produce high latency under load and result in QEMU taking a long t= ime to > > >> > load every single dynamic libraries. > > >>=20 > > >> Acked-by: Ian Jackson > > >=20 > > > Applied. > >=20 > > So is this the "answer" to "Problems with merlot* AMD Opteron 6376 > > systems"? >=20 > It'll be hard to say until this change gets through the Xen push gate > and that version gets used for other branches (linux testing, libvirt, > ovmf, osstest's own gate etc). >=20 Indeed. My opinion is that no, it is not. My understanding of the data Anthony provided is that, under some (difficult to track/analyze/reproduce/etc) load conditions, the Linux IO and VM subsystem suffer from high latency, delaying QEMU startup. In the merlot* cases, the system is completely idle, apart from the failing creation/migration operation. So, no, I don't think that would not be the fix we need for that situation. > At the moment it looks like it has helped with some but not all of the > issues. >=20 > These: >=20 > http://logs.test-lab.xenproject.org/osstest/results/host/merlot0.html > http://logs.test-lab.xenproject.org/osstest/results/host/merlot1.html >=20 Can I ask why (I mean, e.g., comparing what with what) you're saying it seems to have helped? Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-2F1gdjK9XdB8IVoH2b61 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 v2 iEYEABECAAYFAlWk1aEACgkQk4XaBE3IOsRTKACeNu7u+AgVPryoCtzNCBHKPIBg ABEAmwQwPly8kMGPlJdAftlFL2AvtHa1 =abPr -----END PGP SIGNATURE----- --=-2F1gdjK9XdB8IVoH2b61-- --===============2951087429650506424== 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 --===============2951087429650506424==--