Re: [PATCH V4 0/3] basic busy polling support for vhost_net

On 03/10/2016 02:48 PM, Michael Rapoport wrote:

Hi Greg,

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Greg Kurz [off-list ref] wrote on 03/09/2016 09:26:45 PM:

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On Fri,  4 Mar 2016 06:24:50 -0500
Jason Wang [off-list ref] wrote:

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This series tries to add basic busy polling for vhost net. The idea is
simple: at the end of tx/rx processing, busy polling for new tx added
descriptor and rx receive socket for a while. The maximum number of
time (in us) could be spent on busy polling was specified ioctl.

Test A were done through:

- 50 us as busy loop timeout
- Netperf 2.6
- Two machines with back to back connected mlx4

Hi Jason,

Could this also improve performance if both VMs are
on the same host system ?

I've experimented a little with Jason's patches and guest-to-guest netperf 
when both guests were on the same host, and I saw improvements for that 
case.
 

Good to know this, I haven't tested this before but from the codes, it
should work for VM2VM case too.

Thanks a lot for the testing.