Re: [PATCH v3 06/14] RDMA/irdma: Use irq_set_affinity_and_hint

[Nitesh Lal <nilal@redhat.com>]

On Wed, Jul 14, 2021 at 8:03 AM Leon Romanovsky <leonro@nvidia.com> wrote:
>
> On Tue, Jul 13, 2021 at 05:14:54PM -0400, Nitesh Narayan Lal wrote:
> > The driver uses irq_set_affinity_hint() to update the affinity_hint mask
> > that is consumed by the userspace to distribute the interrupts and to apply
> > the provided mask as the affinity for its interrupts. However,
> > irq_set_affinity_hint() applying the provided cpumask as an affinity for
> > the interrupt is an undocumented side effect.
> >
> > To remove this side effect irq_set_affinity_hint() has been marked
> > as deprecated and new interfaces have been introduced. Hence, replace the
> > irq_set_affinity_hint() with the new interface irq_set_affinity_and_hint()
> > where the provided mask needs to be applied as the affinity and
> > affinity_hint pointer needs to be set and replace with
> > irq_update_affinity_hint() where only affinity_hint needs to be updated.
> >
> > Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com>
> > ---
> >  drivers/infiniband/hw/irdma/hw.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/infiniband/hw/irdma/hw.c b/drivers/infiniband/hw/irdma/hw.c
> > index 7afb8a6a0526..7f13a051d4de 100644
> > --- a/drivers/infiniband/hw/irdma/hw.c
> > +++ b/drivers/infiniband/hw/irdma/hw.c
> > @@ -537,7 +537,7 @@ static void irdma_destroy_irq(struct irdma_pci_f *rf,
> >       struct irdma_sc_dev *dev = &rf->sc_dev;
> >
> >       dev->irq_ops->irdma_dis_irq(dev, msix_vec->idx);
> > -     irq_set_affinity_hint(msix_vec->irq, NULL);
> > +     irq_update_affinity_hint(msix_vec->irq, NULL);
> >       free_irq(msix_vec->irq, dev_id);
> >  }
> >
> > @@ -1087,7 +1087,7 @@ irdma_cfg_ceq_vector(struct irdma_pci_f *rf, struct irdma_ceq *iwceq,
> >       }
> >       cpumask_clear(&msix_vec->mask);
> >       cpumask_set_cpu(msix_vec->cpu_affinity, &msix_vec->mask);
> > -     irq_set_affinity_hint(msix_vec->irq, &msix_vec->mask);
> > +     irq_set_affinity_and_hint(msix_vec->irq, &msix_vec->mask);
>
> I think that it needs to be irq_update_affinity_hint().
>

Ah! I got a little confused from our last conversation about mlx5.

IIUC mlx5 sub-function use case uses irdma (?) and that's why I thought
that perhaps we would also want to define the affinity here from the beginning.

In any case, I will make the change and re-post.

--
Thanks
Nitesh