[Lguest] [PATCHv2 RFC 0/4] virtio and vhost-net capacity handling

[Krishna Kumar2]

"Michael S. Tsirkin" <mst at redhat.com> wrote on 06/07/2011 09:38:30 PM:

> > This is on top of the patches applied by Rusty.
> >
> > Warning: untested. Posting now to give people chance to
> > comment on the API.
>
> OK, this seems to have survived some testing so far,
> after I dropped patch 4 and fixed build for patch 3
> (build fixup patch sent in reply to the original).
>
> I'll be mostly offline until Sunday, would appreciate
> testing reports.

Hi Michael,

I ran the latest patches with 1K I/O (guest->local host) and
the results are (60 sec run for each test case):

______________________________
#sessions   BW%       SD%
______________________________
1           -25.6     47.0
2           -29.3     22.9
4              .8     1.6
8             1.6     0
16          -1.6      4.1
32          -5.3      2.1
48           11.3    -7.8
64          -2.8      .7
96          -6.2      .6
128         -10.6     12.7
______________________________
BW: -4.8     SD: 5.4

I tested it again to see if the regression is fleeting (since
the numbers vary quite a bit for 1K I/O even between guest->
local host), but:

______________________________
#sessions  BW%     SD%
______________________________
1          14.0    -17.3
2          19.9    -11.1
4          7.9     -15.3
8          9.6     -13.1
16         1.2     -7.3
32        -.6      -13.5
48        -28.7     10.0
64        -5.7     -.7
96        -9.4     -8.1
128       -9.4      .7
______________________________
BW: -3.7     SD: -2.0


With 16K, there was an improvement in SD, but
higher sessions seem to slightly degrade BW/SD:

______________________________
#sessions  BW%      SD%
______________________________
1          30.9    -25.0
2          16.5    -19.4
4         -1.3      7.9
8          1.4      6.2
16         3.9     -5.4
32         0        4.3
48        -.5        .1
64         32.1    -1.5
96        -2.1      23.2
128       -7.4      3.8
______________________________
BW: 5.0          SD: 7.5


Thanks,

- KK