Re: [PATCH] rcu: remove VLAs

[David Marchand <david.marchand@redhat.com>]

Hello,

On Thu, Apr 10, 2025 at 1:39 PM David Marchand
<david.marchand@redhat.com> wrote:
>
> On Fri, Mar 7, 2025 at 2:40 AM Andre Muezerie
> <andremue@linux.microsoft.com> wrote:
> >
> > There are two lines that were using VLAs, which are not supported by
> > MSVC.
> >
> > 1)
> > ../lib/rcu/rte_rcu_qsbr.c:326:12: warning: variable length array used [-Wvla]
> >   326 |         char data[dq->esize];
> >       |                   ^~~~~~~~~
> > 2)
> > ../lib/rcu/rte_rcu_qsbr.c:389:12: warning: variable length array used [-Wvla]
> >   389 |         char data[dq->esize];
> >       |                   ^~~~~~~~~
> >
> > The short-term fix is to use alloca, to allow progress with the msvc
> > compatibility work.
> > The long-term plan involves API changes and therefore can only be applied
> > with a new release. This long-term plan consists of introducing some
> > reasonable limitation on RCU DQ element size.
> >
> > Signed-off-by: Andre Muezerie <andremue@linux.microsoft.com>
>
> Honnappa, any objection?

I'll take silence as a no.

Andre, you mention long-term plan, if you plan to do this change in
25.11, now would be a good time to prepare a deprecation notice on
this topic.


-- 
David Marchand