2021-07-20 04:49:24

by Ming Lei

Subject: [PATCH V2] genirq/affinity: add helper of irq_affinity_calc_sets

When driver requests to allocate irq affinity managed vectors,
pci_alloc_irq_vectors_affinity() may fallback to single vector
allocation. In this situation, we don't need to call
irq_create_affinity_masks for calling into ->calc_sets() for
avoiding potential memory leak, so add the helper for this purpose.

Fixes: c66d4bd110a1 ("genirq/affinity: Add new callback for (re)calculating interrupt sets")
Reported-by: Bjorn Helgaas <[email protected]>
Cc: [email protected]
Cc: Christoph Hellwig <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
---
V2:
- move WARN_ON_ONCE() into irq_affinity_calc_sets
- don't install default calc_sets() callback as suggested by
Christoph

drivers/pci/msi.c | 3 ++-
include/linux/interrupt.h | 7 +++++++
kernel/irq/affinity.c | 28 +++++++++++++++++-----------
3 files changed, 26 insertions(+), 12 deletions(-)

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 9232255c8515..4e6fbdf0741c 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -1224,7 +1224,8 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
* for the single interrupt case.
*/
if (affd)
- irq_create_affinity_masks(1, affd);
+ irq_affinity_calc_sets(1, affd);
+
pci_intx(dev, 1);
return 1;
}
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 2ed65b01c961..c7ff84d60465 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -340,6 +340,7 @@ irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd);

unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
const struct irq_affinity *affd);
+int irq_affinity_calc_sets(unsigned int affvecs, struct irq_affinity *affd);

#else /* CONFIG_SMP */

@@ -391,6 +392,12 @@ irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
return maxvec;
}

+static inline int irq_affinity_calc_sets(unsigned int affvecs,
+ struct irq_affinity *affd)
+{
+ return 0;
+}
+
#endif /* CONFIG_SMP */

/*
diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
index 4d89ad4fae3b..addd04d68d42 100644
--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -405,6 +405,22 @@ static void default_calc_sets(struct irq_affinity *affd, unsigned int affvecs)
affd->set_size[0] = affvecs;
}

+int irq_affinity_calc_sets(unsigned int affvecs, struct irq_affinity *affd)
+{
+ /*
+ * Simple invocations do not provide a calc_sets() callback. Call
+ * the generic one.
+ */
+ if (!affd->calc_sets)
+ default_calc_sets(affd, affvecs);
+ else
+ affd->calc_sets(affd, affvecs);
+
+ if (WARN_ON_ONCE(affd->nr_sets > IRQ_AFFINITY_MAX_SETS))
+ return -ERANGE;
+ return 0;
+}
+
/**
* irq_create_affinity_masks - Create affinity masks for multiqueue spreading
* @nvecs: The total number of vectors
@@ -429,17 +445,7 @@ irq_create_affinity_masks(unsigned int nvecs, struct irq_affinity *affd)
else
affvecs = 0;

- /*
- * Simple invocations do not provide a calc_sets() callback. Install
- * the generic one.
- */
- if (!affd->calc_sets)
- affd->calc_sets = default_calc_sets;
-
- /* Recalculate the sets */
- affd->calc_sets(affd, affvecs);
-
- if (WARN_ON_ONCE(affd->nr_sets > IRQ_AFFINITY_MAX_SETS))
+ if (irq_affinity_calc_sets(affvecs, affd))
return NULL;

/* Nothing to assign? */
--
2.31.1

2021-07-20 07:53:58

by [email protected]

Subject: Re: [PATCH V2] genirq/affinity: add helper of irq_affinity_calc_sets

> +int irq_affinity_calc_sets(unsigned int affvecs, struct irq_affinity *affd)
> +{
> + /*
> + * Simple invocations do not provide a calc_sets() callback. Call
> + * the generic one.
> + */
> + if (!affd->calc_sets)
> + default_calc_sets(affd, affvecs);
> + else
> + affd->calc_sets(affd, affvecs);

Nit: avoid pointless negations:

if (affd->calc_sets)
affd->calc_sets(affd, affvecs);
else
default_calc_sets(affd, affvecs);

Otherwise looks good:

Reviewed-by: Christoph Hellwig <[email protected]>

2021-07-21 00:06:13

by Bjorn Helgaas

Subject: Re: [PATCH V2] genirq/affinity: add helper of irq_affinity_calc_sets

On Tue, Jul 20, 2021 at 09:50:25AM +0200, Christoph Hellwig wrote:
> > +int irq_affinity_calc_sets(unsigned int affvecs, struct irq_affinity *affd)
> > +{
> > + /*
> > + * Simple invocations do not provide a calc_sets() callback. Call
> > + * the generic one.
> > + */
> > + if (!affd->calc_sets)
> > + default_calc_sets(affd, affvecs);
> > + else
> > + affd->calc_sets(affd, affvecs);
>
> Nit: avoid pointless negations:
>
> if (affd->calc_sets)
> affd->calc_sets(affd, affvecs);
> else
> default_calc_sets(affd, affvecs);

+1

> Otherwise looks good:
>
> Reviewed-by: Christoph Hellwig <[email protected]>

Thanks for doing this! For the PCI part:

Acked-by: Bjorn Helgaas <[email protected]>