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From: "Michael S. Tsirkin" <mst@redhat.com>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: virtualization@lists.linux-foundation.org, kvm@vger.kernel.org,
	netdev@vger.kernel.org
Subject: performance regression in virtio-net in 2.6.32-rc4
Date: Mon, 26 Oct 2009 20:48:35 +0200	[thread overview]
Message-ID: <20091026184835.GB26473@redhat.com> (raw)

Hi!
I noticed a performance regression in virtio net: going from
2.6.31 to 2.6.32-rc4 I see this, for guest to host communication:

[mst@tuck ~]$ ssh robin sh streamtest1
TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 11.0.0.3
(11.0.0.3) port 0 AF_INET : demo
Recv   Send    Send
Socket Socket  Message  Elapsed
Size   Size    Size     Time     Throughput
bytes  bytes   bytes    secs.    10^6bits/sec

 87380  16384  16384    10.20    7806.48


[mst@tuck ~]$ ssh robin sh streamtest1
TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 11.0.0.3
(11.0.0.3) port 0 AF_INET : demo
Recv   Send    Send
Socket Socket  Message  Elapsed
Size   Size    Size     Time     Throughput
bytes  bytes   bytes    secs.    10^6bits/sec

 87380  16384  16384    10.00    6814.60


Note: I had to revert 48925e372f04f5e35fec6269127c62b2c71ab794,
and I applied a patch
	virtio-pci: fix per-vq MSI-X request logic
which fixes a bug introduced by f68d24082e22ccee3077d11aeb6dc5354f0ca7f1.

Any tips on debugging this?

-- 
MST

             reply	other threads:[~2009-10-26 18:48 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-10-26 18:48 Michael S. Tsirkin [this message]
2009-10-27  9:41 ` performance regression in virtio-net in 2.6.32-rc4 Avi Kivity
2009-10-27  9:41 ` Avi Kivity
2009-10-27 23:34 ` Rusty Russell
2009-10-27 23:34 ` Rusty Russell
  -- strict thread matches above, loose matches on Subject: below --
2009-10-26 18:48 Michael S. Tsirkin

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