netdev - Re: [PATCH v1 14/14] net/mlx4: Use irq_update_affinity

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:   Fri, 25 Jun 2021 17:08:03 -0400
From:   Nitesh Lal <nilal@...hat.com>
To:     Leon Romanovsky <leon@...nel.org>
Cc:     Nitesh Narayan Lal <nitesh@...hat.com>,
        linux-kernel@...r.kernel.org, linux-scsi@...r.kernel.org,
        intel-wired-lan@...ts.osuosl.org, netdev@...r.kernel.org,
        linux-api@...r.kernel.org, linux-pci@...r.kernel.org,
        tglx@...utronix.de, jesse.brandeburg@...el.com,
        robin.murphy@....com, mtosatti@...hat.com, mingo@...nel.org,
        jbrandeb@...nel.org, frederic@...nel.org, juri.lelli@...hat.com,
        abelits@...vell.com, bhelgaas@...gle.com, rostedt@...dmis.org,
        peterz@...radead.org, davem@...emloft.net,
        akpm@...ux-foundation.org, sfr@...b.auug.org.au,
        stephen@...workplumber.org, rppt@...ux.vnet.ibm.com,
        chris.friesen@...driver.com, maz@...nel.org, nhorman@...driver.com,
        pjwaskiewicz@...il.com, sassmann@...hat.com, thenzl@...hat.com,
        kashyap.desai@...adcom.com, sumit.saxena@...adcom.com,
        shivasharan.srikanteshwara@...adcom.com,
        sathya.prakash@...adcom.com, sreekanth.reddy@...adcom.com,
        suganath-prabu.subramani@...adcom.com, james.smart@...adcom.com,
        dick.kennedy@...adcom.com, jkc@...hat.com, faisal.latif@...el.com,
        shiraz.saleem@...el.com, tariqt@...dia.com, ahleihel@...hat.com,
        kheib@...hat.com, borisp@...dia.com, saeedm@...dia.com,
        benve@...co.com, govind@....com, jassisinghbrar@...il.com,
        luobin9@...wei.com, ajit.khaparde@...adcom.com,
        sriharsha.basavapatna@...adcom.com, somnath.kotur@...adcom.com
Subject: Re: [PATCH v1 14/14] net/mlx4: Use irq_update_affinity_hint

On Mon, Jun 21, 2021 at 4:02 AM Leon Romanovsky <leon@...nel.org> wrote:
>
> On Thu, Jun 17, 2021 at 02:22:42PM -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. However,
> > under the hood irq_set_affinity_hint() also applies the provided cpumask
> > (if not NULL) as the affinity for the given interrupt which 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_update_affinity_hint()
> > that only updates the affinity_hint pointer.
> >
> > Signed-off-by: Nitesh Narayan Lal <nitesh@...hat.com>
> > ---
> >  drivers/net/ethernet/mellanox/mlx4/eq.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/mellanox/mlx4/eq.c b/drivers/net/ethernet/mellanox/mlx4/eq.c
> > index 9e48509ed3b2..f549d697ca95 100644
> > --- a/drivers/net/ethernet/mellanox/mlx4/eq.c
> > +++ b/drivers/net/ethernet/mellanox/mlx4/eq.c
> > @@ -244,9 +244,9 @@ static void mlx4_set_eq_affinity_hint(struct mlx4_priv *priv, int vec)
> >           cpumask_empty(eq->affinity_mask))
> >               return;
> >
> > -     hint_err = irq_set_affinity_hint(eq->irq, eq->affinity_mask);
> > +     hint_err = irq_update_affinity_hint(eq->irq, eq->affinity_mask);
> >       if (hint_err)
> > -             mlx4_warn(dev, "irq_set_affinity_hint failed, err %d\n", hint_err);
> > +             mlx4_warn(dev, "irq_update_affinity_hint failed, err %d\n", hint_err);
> >  }
> >  #endif
> >
> > @@ -1124,7 +1124,7 @@ static void mlx4_free_irqs(struct mlx4_dev *dev)
> >               if (eq_table->eq[i].have_irq) {
> >                       free_cpumask_var(eq_table->eq[i].affinity_mask);
> >  #if defined(CONFIG_SMP)
> > -                     irq_set_affinity_hint(eq_table->eq[i].irq, NULL);
> > +                     irq_update_affinity_hint(eq_table->eq[i].irq, NULL);
> >  #endif
>
> This #if/endif can be deleted.

I think we also can get rid of the other #if/endif CONFIG_SMP
occurrences that are present around mlx4_set_eq_affinity_hint()
definition and call, isn't it?
There is already a check-in interrupt.h so doing it again in the
driver looks like an unwanted repetition IMHO.

>
> Thanks,
> Reviewed-by: Leon Romanovsky <leonro@...dia.com>
>


-- 
Thanks
Nitesh