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* performance regression in virtio-net in 2.6.32-rc4
@ 2009-10-26 18:48 Michael S. Tsirkin
  2009-10-27  9:41 ` Avi Kivity
  2009-10-27 23:34 ` Rusty Russell
  0 siblings, 2 replies; 3+ messages in thread
From: Michael S. Tsirkin @ 2009-10-26 18:48 UTC (permalink / raw)
  To: Rusty Russell; +Cc: virtualization, kvm, netdev

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

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: performance regression in virtio-net in 2.6.32-rc4
  2009-10-26 18:48 performance regression in virtio-net in 2.6.32-rc4 Michael S. Tsirkin
@ 2009-10-27  9:41 ` Avi Kivity
  2009-10-27 23:34 ` Rusty Russell
  1 sibling, 0 replies; 3+ messages in thread
From: Avi Kivity @ 2009-10-27  9:41 UTC (permalink / raw)
  To: Michael S. Tsirkin; +Cc: Rusty Russell, virtualization, kvm, netdev

On 10/26/2009 08:48 PM, Michael S. Tsirkin wrote:
> 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:
>
> Any tips on debugging this?
>    

Lacking better advice, a bisect can help as a last resort.  'git bisect 
start -- drivers/net drivers/virtio' will probably find it fastest.

-- 
error compiling committee.c: too many arguments to function


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: performance regression in virtio-net in 2.6.32-rc4
  2009-10-26 18:48 performance regression in virtio-net in 2.6.32-rc4 Michael S. Tsirkin
  2009-10-27  9:41 ` Avi Kivity
@ 2009-10-27 23:34 ` Rusty Russell
  1 sibling, 0 replies; 3+ messages in thread
From: Rusty Russell @ 2009-10-27 23:34 UTC (permalink / raw)
  To: Michael S. Tsirkin; +Cc: virtualization, kvm, netdev

On Tue, 27 Oct 2009 05:18:35 am Michael S. Tsirkin wrote:
> 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:
...
> Size   Size    Size     Time     Throughput
> bytes  bytes   bytes    secs.    10^6bits/sec
> 
>  87380  16384  16384    10.20    7806.48
...
>  87380  16384  16384    10.00    6814.60

Hmm, needs a bisect I'd say.

Thanks,
Rusty.

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2009-10-27 23:34 UTC | newest]

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2009-10-26 18:48 performance regression in virtio-net in 2.6.32-rc4 Michael S. Tsirkin
2009-10-27  9:41 ` Avi Kivity
2009-10-27 23:34 ` Rusty Russell

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