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authorChristoph Hellwig <hch@lst.de>2017-08-17 12:24:47 +0200
committerJens Axboe <axboe@kernel.dk>2017-08-18 08:08:14 -0600
commitc005390374957baacbc38eef96ea360559510aa7 (patch)
tree6055f163f22d993bcf03ed965510a45a8d28745b
parent6caa0503c43d65de92309b967b5b1aa289af303b (diff)
downloadlwn-c005390374957baacbc38eef96ea360559510aa7.tar.gz
lwn-c005390374957baacbc38eef96ea360559510aa7.zip
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>
-rw-r--r--block/blk-mq-pci.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/block/blk-mq-pci.c b/block/blk-mq-pci.c
index 0c3354cf3552..76944e3271bf 100644
--- a/block/blk-mq-pci.c
+++ b/block/blk-mq-pci.c
@@ -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);