lkml.org 
[lkml]   [2016]   [May]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH 2/5] genirq: Allow the affinity of a percpu interrupt to be set/retrieved
    From
    Date
    Hi Geert,

    On 19/05/16 12:08, Geert Uytterhoeven wrote:
    > Hi Marc,
    >
    > On Mon, Apr 11, 2016 at 10:57 AM, Marc Zyngier <marc.zyngier@arm.com> wrote:
    >> In order to prepare the genirq layer for the concept of partitionned
    >> percpu interrupts, let's allow an affinity to be associated with
    >> such an interrupt. We introduce:
    >>
    >> - irq_set_percpu_devid_partition: flag an interrupt as a percpu-devid
    >> interrupt, and associate it with an affinity
    >> - irq_get_percpu_devid_partition: allow the affinity of that interrupt
    >> to be retrieved.
    >>
    >> This will allow a driver to discover which CPUs the per-cpu interrupt
    >> can actually fire on.
    >>
    >> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
    >
    >> --- a/include/linux/irqdesc.h
    >> +++ b/include/linux/irqdesc.h
    >> @@ -66,6 +66,7 @@ struct irq_desc {
    >> int threads_handled_last;
    >> raw_spinlock_t lock;
    >> struct cpumask *percpu_enabled;
    >> + const struct cpumask *percpu_affinity;
    >
    > Adding this field showed up on my bloat-o-meter radar...

    By how much?

    > Does it make sense to move it (and percpu_enabled) inside the "#ifdef
    > CONFIG_SMP" below, and rework the code to not need it on UP?
    >
    >> #ifdef CONFIG_SMP
    >> const struct cpumask *affinity_hint;
    >> struct irq_affinity_notify *affinity_notify;

    I wonder if we couldn't actually unify affinity_hint and
    percpu_affinity. I'll have a look.

    Thanks,

    M.
    --
    Jazz is not dead. It just smells funny...

    \
     
     \ /
      Last update: 2016-05-19 15:21    [W:4.300 / U:0.016 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site