[PATCH] eal: fix alignment of RISCV xmm vector type

[Morten Brørup]

> From: Stanisław Kardach [mailto:kda at semihalf.com]
> Sent: Thursday, 16 November 2023 00.21
> 
> On Wed, Nov 15, 2023 at 10:31 PM Morten Brørup
> <mb at smartsharesystems.com> wrote:
> >
> > > From: Tyler Retzlaff [mailto:roretzla at linux.microsoft.com]
> > > Sent: Wednesday, 15 November 2023 22.17
> > >
> > > Fix the alignment for rte_xmm_t it should be 16 instead of 8 bytes.
> > >
> > > Fixes: f22e705ebf12 ("eal/riscv: support RISC-V architecture")
> > > Cc: maz at semihalf.com
> > > Cc: stable at dpdk.org
> > > Signed-off-by: Tyler Retzlaff <roretzla at linux.microsoft.com>
> > > ---
> >
> > Reviewed-by: Morten Brørup <mb at smartsharesystems.com>
> >
> > As mentioned in the other thread:
> >
> > We need to urgently decide if this bug should live on in DPDK 23.11,
> or if the fix should be included although we are very late in the
> release process.
> >
> > Stanislaw, what do you think?
> Good catch! As for backporting I'm not sure of the urgency given that
> our examples still use scalar instructions for handling xmm_t. The
> question is whether there is a platform in use which has vector
> extensions enabled and that utilizes DPDK. I'm not that sure of it
> though I'd be happy to be proven wrong.

Can we extrapolate this, and also conclude that postponing this bugfix until the next ABI/API breaking release, DPDK 24.11, is not really going to hurt anyone?

Stanislaw, please confirm?

Bruce, I don't feel 100 % confident in making this postponement recommendation. Could you please provide a second opinion regarding the timing of fixing this bug? Or rather: do you have any strong arguments *against* postponing it to DPDK 24.11?

> 
> Reviewed-by: Stanislaw Kardach <kda at semihalf.com>
> 
> >
> > Furthermore, I wonder if it can be backported to stable, and to what
> extent backporting it would break the ABI/API.

Based on your input regarding the current deployment status, backporting the bugfix clearly isn't worth the effort. Excellent!

> >
> 
> 
> --
> Best Regards,
> Stanisław Kardach