Re: [Virtio-fs] tools/virtiofs: Multi threading seems to hurt performance

[Chirantan Ekbote]

On Sat, Sep 19, 2020 at 6:36 AM Vivek Goyal <vgoyal@redhat.com> wrote:
>
> Hi All,
>
> virtiofsd default thread pool size is 64. To me it feels that in most of
> the cases thread pool size 1 performs better than thread pool size 64.
>
> I ran virtiofs-tests.
>
> https://github.com/rhvgoyal/virtiofs-tests
>
> And here are the comparision results. To me it seems that by default
> we should switch to 1 thread (Till we can figure out how to make
> multi thread performance better even when single process is doing
> I/O in client).
>

FWIW, we've observed the same behavior in crosvm. Using a thread pool
for the virtiofs server consistently gave us worse performance than
using a single thread.

Chirantan