PCI/MSI: Ignore affinity if pre/post vector count is more than min_vecs

min_vecs is the minimum amount of vectors needed to operate in MSI-X mode
which may just include the vectors that don't need affinity.

Disabling affinity settings causes the qla2xxx driver scsi_add_host() to fail
when blk_mq is enabled as the blk_mq_pci_map_queues() expects affinity masks
on each vector.

Fixes: dfef358bd1 ("PCI/MSI: Don't apply affinity if there aren't enough vectors left")
Signed-off-by: Michael Hernandez <michael.hernandez@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org	# v4.10+
This commit is contained in:
Michael Hernandez
2017-05-18 10:47:47 -07:00
committed by Bjorn Helgaas
parent 2ea659a9ef
commit 6f9a22bc57
3 changed files with 16 additions and 15 deletions

View File

@@ -66,6 +66,13 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
struct cpumask *masks;
cpumask_var_t nmsk;
/*
* If there aren't any vectors left after applying the pre/post
* vectors don't bother with assigning affinity.
*/
if (!affv)
return NULL;
if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL))
return NULL;
@@ -140,15 +147,19 @@ out:
/**
* irq_calc_affinity_vectors - Calculate the optimal number of vectors
* @minvec: The minimum number of vectors available
* @maxvec: The maximum number of vectors available
* @affd: Description of the affinity requirements
*/
int irq_calc_affinity_vectors(int maxvec, const struct irq_affinity *affd)
int irq_calc_affinity_vectors(int minvec, int maxvec, const struct irq_affinity *affd)
{
int resv = affd->pre_vectors + affd->post_vectors;
int vecs = maxvec - resv;
int cpus;
if (resv > minvec)
return 0;
/* Stabilize the cpumasks */
get_online_cpus();
cpus = cpumask_weight(cpu_online_mask);