Re: [Qemu-devel] [PATCH 2/4] libvhost-user: support many virtqueues

[Stefan Hajnoczi <stefanha@redhat.com>]

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On Fri, Jun 21, 2019 at 03:48:36PM +0200, Marc-André Lureau wrote:
> On Fri, Jun 21, 2019 at 11:40 AM Stefan Hajnoczi <stefanha@redhat.com> wrote:
> > diff --git a/contrib/vhost-user-blk/vhost-user-blk.c b/contrib/vhost-user-blk/vhost-user-blk.c
> > index 86a3987744..ae61034656 100644
> > --- a/contrib/vhost-user-blk/vhost-user-blk.c
> > +++ b/contrib/vhost-user-blk/vhost-user-blk.c
> > @@ -25,6 +25,10 @@
> >  #include <sys/ioctl.h>
> >  #endif
> >
> > +enum {
> > +    VHOST_USER_BLK_MAX_QUEUES = 8,
> > +};
> 
> why do you use enum,(and not const int) ? (similarly for other devices)
> 
> other than than
> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

This is how I was taught when I was a little boy.

With an actual variable there's a risk that the compiler reserves space
for a variable when you actually just need a constant.  Whether modern
compilers do that or not, I don't know.

The type is clearer when a variable is used instead of an enum.

Pros and cons...

Stefan

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