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nvme: provide optimized poll function for separate poll queues
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If we have separate poll queues, we know that they aren't using
interrupts. Hence we don't need to disable interrupts around
finding completions.

Provide a separate set of blk_mq_ops for such devices.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Jens Axboe committed Nov 16, 2018
1 parent 9334ae5 commit dabcefa
Showing 1 changed file with 37 additions and 8 deletions.
45 changes: 37 additions & 8 deletions drivers/nvme/host/pci.c
Original file line number Diff line number Diff line change
@@ -1082,6 +1082,23 @@ static int nvme_poll(struct blk_mq_hw_ctx *hctx, unsigned int tag)
return __nvme_poll(nvmeq, tag);
}

static int nvme_poll_noirq(struct blk_mq_hw_ctx *hctx, unsigned int tag)
{
struct nvme_queue *nvmeq = hctx->driver_data;
u16 start, end;
bool found;

if (!nvme_cqe_pending(nvmeq))
return 0;

spin_lock(&nvmeq->cq_lock);
found = nvme_process_cq(nvmeq, &start, &end, tag);
spin_unlock(&nvmeq->cq_lock);

nvme_complete_cqes(nvmeq, start, end);
return found;
}

static void nvme_pci_submit_async_event(struct nvme_ctrl *ctrl)
{
struct nvme_dev *dev = to_nvme_dev(ctrl);
@@ -1584,17 +1601,25 @@ static const struct blk_mq_ops nvme_mq_admin_ops = {
.timeout = nvme_timeout,
};

#define NVME_SHARED_MQ_OPS \
.queue_rq = nvme_queue_rq, \
.rq_flags_to_type = nvme_rq_flags_to_type, \
.complete = nvme_pci_complete_rq, \
.init_hctx = nvme_init_hctx, \
.init_request = nvme_init_request, \
.map_queues = nvme_pci_map_queues, \
.timeout = nvme_timeout \

static const struct blk_mq_ops nvme_mq_ops = {
.queue_rq = nvme_queue_rq,
.rq_flags_to_type = nvme_rq_flags_to_type,
.complete = nvme_pci_complete_rq,
.init_hctx = nvme_init_hctx,
.init_request = nvme_init_request,
.map_queues = nvme_pci_map_queues,
.timeout = nvme_timeout,
NVME_SHARED_MQ_OPS,
.poll = nvme_poll,
};

static const struct blk_mq_ops nvme_mq_poll_noirq_ops = {
NVME_SHARED_MQ_OPS,
.poll = nvme_poll_noirq,
};

static void nvme_dev_remove_admin(struct nvme_dev *dev)
{
if (dev->ctrl.admin_q && !blk_queue_dying(dev->ctrl.admin_q)) {
@@ -2276,7 +2301,11 @@ static int nvme_dev_add(struct nvme_dev *dev)
int ret;

if (!dev->ctrl.tagset) {
dev->tagset.ops = &nvme_mq_ops;
if (!dev->io_queues[NVMEQ_TYPE_POLL])
dev->tagset.ops = &nvme_mq_ops;
else
dev->tagset.ops = &nvme_mq_poll_noirq_ops;

dev->tagset.nr_hw_queues = dev->online_queues - 1;
dev->tagset.nr_maps = NVMEQ_TYPE_NR;
dev->tagset.timeout = NVME_IO_TIMEOUT;

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