From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gregory Haskins Subject: Re: [PATCH 0/7] AlacrityVM guest drivers Date: Fri, 07 Aug 2009 14:04:05 -0400 Message-ID: <4A7C6C95.7020008@gmail.com> References: <20090803171030.17268.26962.stgit@dev.haskins.net> <20090806081955.GA9752@redhat.com> <4A7C37E5.4040302@codemonkey.ws> <4A7C42C8.5050608@gmail.com> <4A7C4C50.5040503@codemonkey.ws> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigF78B3F0A78DC3F64F403EF27" Cc: "Michael S. Tsirkin" , Gregory Haskins , linux-kernel@vger.kernel.org, alacrityvm-devel@lists.sourceforge.net, netdev@vger.kernel.org, kvm@vger.kernel.org To: Anthony Liguori Return-path: In-Reply-To: <4A7C4C50.5040503@codemonkey.ws> Sender: kvm-owner@vger.kernel.org List-Id: netdev.vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigF78B3F0A78DC3F64F403EF27 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Anthony Liguori wrote: > Gregory Haskins wrote: >> That said, note that the graphs were from earlier kernel runs (2.6.28,= >> 29-rc8). The most recent data I can find that I published is for >> 2.6.29, announced with the vbus-v3 release back in April: >> >> http://lkml.org/lkml/2009/4/21/408 >> >> In it, the virtio-net throughput numbers are substantially higher and >> possibly more in line with your expectations (4.5gb/s) (though notably= >> still lagging venet, which weighed in at 5.6gb/s). >> =20 >=20 > Okay, that makes more sense. Would be nice to update the graphs as the= y > make virtio look really, really bad :-) Yeah, they are certainly ripe for an update. (Note that I was unilaterally stale on venet numbers, too) ;) >=20 >> Generally, I find that the virtio-net exhibits non-deterministic resul= ts >> from release to release. I suspect (as we have discussed) the >> tx-mitigation scheme. Some releases buffer the daylights out of the >> stream, and virtio gets close(r) throughput (e.g. 4.5g vs 5.8g, but >> absolutely terrible latency (4000us vs 65us). Other releases it seems= >> to operate with more of a compromise (1.3gb/s vs 3.8gb/s, but 350us vs= >> 85us). >> =20 >=20 > Are you using kvm modules or a new kernel? I just build the entire kernel from git. > There was some timer > infrastructure changes around 28/29 and it's possible that the system > your on is now detecting an hpet which will result in a better time > source. That could have an affect on mitigation. Yeah, I suspect you are right. I always kept the .config and machine constant, but I *do* bounce around kernel versions so perhaps I got hosed by a make-oldconfig cycle somewhere along the way. >=20 >> If there is another patch-series/tree I should be using for comparison= , >> please point me at it. >> =20 >=20 > No, I think it's fair to look at upstream Linux. Looking at the latest= > bits would be nice though because there are some virtio friendly change= s > recently like MSI-x and GRO. Yeah, I will definitely include kvm.git in addition to whatever is current from Linus. I already have adopted using the latest qemu-kvm.git into my workflow. Regards, -Greg --------------enigF78B3F0A78DC3F64F403EF27 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.11 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkp8bJUACgkQP5K2CMvXmqHs+gCfRyYqGSgtnS8hkuH/K4N8SyEA Ez8Anj/LAO66fxdRYI3elp6czuQYokpf =m3aa -----END PGP SIGNATURE----- --------------enigF78B3F0A78DC3F64F403EF27--