Re: [PATCH V3 3/5] genirq/affinity: add new callback for caculating set vectors

Bjorn Helgaas
2019-02-13T15:11:54Z

On Wed, Feb 13, 2019 at 06:50:39PM +0800, Ming Lei wrote:
> Currently pre-caculated set vectors are provided by driver for
> allocating & spread vectors. This way only works when drivers passes
> same 'max_vecs' and 'min_vecs' to pci_alloc_irq_vectors_affinity(),
> also requires driver to retry the allocating & spread.

s/pre-caculated/precalculated/
s/drivers/a driver/
s/also requires/which also requires the/

> As Bjorn and Keith mentioned, the current usage & interface for irq sets
> is a bit awkward because the retrying should have been avoided by providing
> one resonable 'min_vecs'. However, if 'min_vecs' isn't same with
> 'max_vecs', number of the allocated vectors is unknown before calling
> pci_alloc_irq_vectors_affinity(), then each set's vectors can't be
> pre-caculated.

s/resonable/reasonable/
s/isn't same with/isn't the same as/
s/number of/the number of/
s/pre-caculated/precalculated/
s/then each/and the/
s/irq/IRQ/

> Add a new callback of .calc_sets into 'struct irq_affinity' so that
> driver can caculate set vectors after IRQ vector is allocated and
> before spread IRQ vectors. Add 'priv' so that driver may retrieve
> its private data via the 'struct irq_affinity'.

s/caculate/calculate/

I *think* "set vectors" here has something to do with an affinity
cpumask? "Set vectors" doesn't seem like quite the right terminology.

> Suggested-by: Thomas Gleixner <tglx@linutronix.de>
> Signed-off-by: Ming Lei <ming.lei@redhat.com>
> ---
> include/linux/interrupt.h | 4 ++++
> kernel/irq/affinity.c | 8 ++++++--
> 2 files changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
> index a20150627a32..7a27f6ba1f2f 100644
> --- a/include/linux/interrupt.h
> +++ b/include/linux/interrupt.h
> @@ -269,12 +269,16 @@ struct irq_affinity_notify {
> * the MSI(-X) vector space
> * @nr_sets: Length of passed in *sets array
> * @set_vectors: Number of affinitized sets
> + * @calc_sets: Callback for caculating set vectors

Possible s/set vectors/<something else>/ ?

> + * @priv: Private data of @calc_sets
> */
> struct irq_affinity {
> int pre_vectors;
> int post_vectors;
> int nr_sets;
> int set_vectors[IRQ_MAX_SETS];
> + void (*calc_sets)(struct irq_affinity *, int nvecs);
> + void *priv;
> };
>
> /**
> diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
> index b868b9d3df7f..2341b1f005fa 100644
> --- a/kernel/irq/affinity.c
> +++ b/kernel/irq/affinity.c
> @@ -267,7 +267,9 @@ irq_create_affinity_masks(int nvecs, struct irq_affinity *affd)
> * Spread on present CPUs starting from affd->pre_vectors. If we
> * have multiple sets, build each sets affinity mask separately.
> */
> - if (!affd->nr_sets) {
> + if (affd->calc_sets) {
> + affd->calc_sets(affd, nvecs);
> + } else if (!affd->nr_sets) {
> affd->nr_sets = 1;
> affd->set_vectors[0] = affvecs;
> }
> @@ -316,7 +318,9 @@ int irq_calc_affinity_vectors(int minvec, int maxvec, const struct irq_affinity
> if (resv > minvec)
> return 0;
>
> - if (affd->nr_sets) {
> + if (affd->calc_sets) {
> + set_vecs = vecs;
> + } else if (affd->nr_sets) {
> int i;
>
> for (i = 0, set_vecs = 0; i < affd->nr_sets; i++)
> --
> 2.9.5
>