Re: [Qemu-devel] [PATCH v1 00/17] dataplane: optimization and multi virtqueue support

[Kevin Wolf <kwolf@redhat.com>]

Am 05.08.2014 um 11:50 hat Ming Lei geschrieben:
> On Tue, Aug 5, 2014 at 5:38 PM, Stefan Hajnoczi <stefanha@redhat.com> wrote:
> > On Tue, Aug 05, 2014 at 11:33:01AM +0800, Ming Lei wrote:
> >> These patches bring up below 4 changes:
> >>         - introduce object allocation pool and apply it to
> >>         virtio-blk dataplane for improving its performance
> >>
> >>         - introduce selective coroutine bypass mechanism
> >>         for improving performance of virtio-blk dataplane with
> >>         raw format image
> >>
> >>         - linux-aio changes: fixing for cases of -EAGAIN and partial
> >>         completion, increase max events to 256, and remove one unuseful
> >>         fields in 'struct qemu_laiocb'
> >>
> >>         - support multi virtqueue for virtio-blk
> >
> > Please split up this patch series into separate patch series.
> >
> > These are independent changes and there is no reason to combine them.
> > You're doing yourself a disservice because changes that are ready to be
> > applied are getting held up by those that still need more discussion.
> 
> Without previous optimization patches, the mq conversion can't
> obtain so much improvement, that is why I put them together.
> 
> Also mq conversion depends on linux-aio fix too.
> 
> Also it becomes a difficult to test these patches if they are splitted,
> and describing the dependency is a bit annoying too.
> 
> > That will also make the performance discussions easier to follow since
> > each patch series should include performance results, making it easy to
> > understand how much improvement each change brings.
> 
> The number can be found inside patches, for example, patch 02 has
> the number for using obj pool, and patch 09 has the number for
> bypassing coroutine, and patch 17 has the number for mq conversion.

A claim like "~5%-10% throughput improvement" isn't numbers nor a
precise description of your benchmark setup.

Kevin