blk-mq-pci: add a fallback when pci_irq_get_affinity returns NULL

While pci_irq_get_affinity should never fail for SMP kernel that
implement the affinity mapping, it will always return NULL in the
UP case, so provide a fallback mapping of all queues to CPU 0 in
that case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2017-08-17 12:24:47 +02:00 committed by Jens Axboe
parent 6caa0503c4
commit c005390374
1 changed files with 7 additions and 1 deletions

View File

@ -36,12 +36,18 @@ int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev)
for (queue = 0; queue < set->nr_hw_queues; queue++) {
mask = pci_irq_get_affinity(pdev, queue);
if (!mask)
return -EINVAL;
goto fallback;
for_each_cpu(cpu, mask)
set->mq_map[cpu] = queue;
}
return 0;
fallback:
WARN_ON_ONCE(set->nr_hw_queues > 1);
for_each_possible_cpu(cpu)
set->mq_map[cpu] = 0;
return 0;
}
EXPORT_SYMBOL_GPL(blk_mq_pci_map_queues);