Virtualization - Dec 2022 - [RFC PATCH 2/9] vringh: remove vringh_iov and unite to vringh_kiov

2022?12?27?(?) 16:05 Michael S. Tsirkin <mst at
redhat.com>:
>
> On Tue, Dec 27, 2022 at 02:04:03PM +0800, Jason Wang wrote:
> > On Tue, Dec 27, 2022 at 10:25 AM Shunsuke Mie <mie at
igel.co.jp> wrote:
> > >
> > > struct vringh_iov is defined to hold userland addresses. However,
to use
> > > common function, __vring_iov, finally the vringh_iov converts to
the
> > > vringh_kiov with simple cast. It includes compile time check code
to make
> > > sure it can be cast correctly.
> > >
> > > To simplify the code, this patch removes the struct vringh_iov
and unifies
> > > APIs to struct vringh_kiov.
> > >
> > > Signed-off-by: Shunsuke Mie <mie at igel.co.jp>
> >
> > While at this, I wonder if we need to go further, that is, switch to
> > using an iov iterator instead of a vringh customized one.
> >
> > Thanks
>
> Possibly, but when doing changes like this one needs to be careful
> to avoid breaking all the inlining tricks vringh relies on for
> performance.
Definitely, I'm evaluating the performance using vringh_test. I'll add a
result of the evaluation. But, If there are other evaluation methods, could you
please tell me?
> --
> MST
>
Best,
Shunsuke

On Tue, Dec 27, 2022 at 04:13:49PM +0900, Shunsuke Mie
wrote:
> 2022?12?27?(?) 16:05 Michael S. Tsirkin <mst at redhat.com>:
> >
> > On Tue, Dec 27, 2022 at 02:04:03PM +0800, Jason Wang wrote:
> > > On Tue, Dec 27, 2022 at 10:25 AM Shunsuke Mie <mie at
igel.co.jp> wrote:
> > > >
> > > > struct vringh_iov is defined to hold userland addresses.
However, to use
> > > > common function, __vring_iov, finally the vringh_iov
converts to the
> > > > vringh_kiov with simple cast. It includes compile time check
code to make
> > > > sure it can be cast correctly.
> > > >
> > > > To simplify the code, this patch removes the struct
vringh_iov and unifies
> > > > APIs to struct vringh_kiov.
> > > >
> > > > Signed-off-by: Shunsuke Mie <mie at igel.co.jp>
> > >
> > > While at this, I wonder if we need to go further, that is, switch
to
> > > using an iov iterator instead of a vringh customized one.
> > >
> > > Thanks
> >
> > Possibly, but when doing changes like this one needs to be careful
> > to avoid breaking all the inlining tricks vringh relies on for
> > performance.
> Definitely, I'm evaluating the performance using vringh_test. I'll
add a
> result of the evaluation. But, If there are other evaluation methods, could
you
> please tell me?
high level tests over virtio blk and net are possible, but let's
start with vringh_test.
> > --
> > MST
> >
> 
> Best,
> Shunsuke