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nvme-pci: Separate IO and admin queue IRQ vectors

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The admin and first IO queues shared the first irq vector, which has an
affinity mask including cpu0. If a system allows cpu0 to be offlined,
the admin queue may not be usable if no other CPUs in the affinity mask
are online. This is a problem since unlike IO queues, there is only
one admin queue that always needs to be usable.

To fix, this patch allocates one pre_vector for the admin queue that
is assigned all CPUs, so will always be accessible. The IO queues are
assigned the remaining managed vectors.

In case a controller has only one interrupt vector available, the admin
and IO queues will share the pre_vector with all CPUs assigned.

Cc: Jianchao Wang <jianchao.w.wang@oracle.com>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Keith Busch 2018-04-12 09:16:10 -06:00 committed by Jens Axboe
parent a6ff7262c2
commit 22b5560195
1 changed files with 17 additions and 6 deletions
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23
drivers/nvme/host/pci.c
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@ -84,6 +84,7 @@ struct nvme_dev {
struct dma_pool *prp_small_pool;
unsigned online_queues;
unsigned max_qid;
unsigned int num_vecs;
int q_depth;
u32 db_stride;
void __iomem *bar;
@ -414,7 +415,8 @@ static int nvme_pci_map_queues(struct blk_mq_tag_set *set)
{
struct nvme_dev *dev = set->driver_data;
return blk_mq_pci_map_queues(set, to_pci_dev(dev->dev), 0);
return blk_mq_pci_map_queues(set, to_pci_dev(dev->dev),
dev->num_vecs > 1 ? 1 /* admin queue */ : 0);
}
/**
@ -1456,7 +1458,11 @@ static int nvme_create_queue(struct nvme_queue *nvmeq, int qid)
nvmeq->sq_cmds_io = dev->cmb + offset;
}
nvmeq->cq_vector = qid - 1;
/*
* A queue's vector matches the queue identifier unless the controller
* has only one vector available.
*/
nvmeq->cq_vector = dev->num_vecs == 1 ? 0 : qid;
result = adapter_alloc_cq(dev, qid, nvmeq);
if (result < 0)
goto release_vector;
@ -1910,6 +1916,10 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
int result, nr_io_queues;
unsigned long size;
struct irq_affinity affd = {
.pre_vectors = 1
};
nr_io_queues = num_possible_cpus();
result = nvme_set_queue_count(&dev->ctrl, &nr_io_queues);
if (result < 0)
@ -1945,11 +1955,12 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
* setting up the full range we need.
*/
pci_free_irq_vectors(pdev);
nr_io_queues = pci_alloc_irq_vectors(pdev, 1, nr_io_queues,
PCI_IRQ_ALL_TYPES | PCI_IRQ_AFFINITY);
if (nr_io_queues <= 0)
result = pci_alloc_irq_vectors_affinity(pdev, 1, nr_io_queues + 1,
PCI_IRQ_ALL_TYPES | PCI_IRQ_AFFINITY, &affd);
if (result <= 0)
return -EIO;
dev->max_qid = nr_io_queues;
dev->num_vecs = result;
dev->max_qid = max(result - 1, 1);
/*
* Should investigate if there's a performance win from allocating