nvme/pci: Poll CQ on timeout

If an IO timeout occurs, it's helpful to know if the controller did not
post a completion or the driver missed an interrupt. While we never expect
the latter, this patch will make it possible to tell the difference so
we don't have to guess.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
This commit is contained in:
Keith Busch 2017-02-24 17:59:28 -05:00 committed by Christoph Hellwig
parent 4363135761
commit 7776db1ccc
1 changed files with 18 additions and 3 deletions

View File

@ -846,10 +846,8 @@ static irqreturn_t nvme_irq_check(int irq, void *data)
return IRQ_NONE;
}
static int nvme_poll(struct blk_mq_hw_ctx *hctx, unsigned int tag)
static int __nvme_poll(struct nvme_queue *nvmeq, unsigned int tag)
{
struct nvme_queue *nvmeq = hctx->driver_data;
if (nvme_cqe_valid(nvmeq, nvmeq->cq_head, nvmeq->cq_phase)) {
spin_lock_irq(&nvmeq->q_lock);
__nvme_process_cq(nvmeq, &tag);
@ -862,6 +860,13 @@ static int nvme_poll(struct blk_mq_hw_ctx *hctx, unsigned int tag)
return 0;
}
static int nvme_poll(struct blk_mq_hw_ctx *hctx, unsigned int tag)
{
struct nvme_queue *nvmeq = hctx->driver_data;
return __nvme_poll(nvmeq, tag);
}
static void nvme_pci_submit_async_event(struct nvme_ctrl *ctrl, int aer_idx)
{
struct nvme_dev *dev = to_nvme_dev(ctrl);
@ -959,6 +964,16 @@ static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
struct request *abort_req;
struct nvme_command cmd;
/*
* Did we miss an interrupt?
*/
if (__nvme_poll(nvmeq, req->tag)) {
dev_warn(dev->ctrl.device,
"I/O %d QID %d timeout, completion polled\n",
req->tag, nvmeq->qid);
return BLK_EH_HANDLED;
}
/*
* Shutdown immediately if controller times out while starting. The
* reset work will see the pci device disabled when it gets the forced