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nvme: fix irq vs io_queue calculations

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Guenter reported an boot hang issue on HPPA after we default to 0 poll
queues. We have two issues in the queue count calculations:

1) We don't separate the poll queues from the read/write queues. This is
   important, since the former doesn't need interrupts.
2) The adjust logic is broken.

Adjust the poll queue count before doing nvme_calc_io_queues(). The poll
queue count is only limited by the IO queue count we were able to get
from the controller, not failures in the IRQ allocation loop. This
leaves nvme_calc_io_queues() just adjusting the read/write queue map.

Reported-by: Reported-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2018-12-09 11:21:45 -07:00
parent b7934ba414
commit 6451fe73fa
1 changed files with 29 additions and 35 deletions
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64
drivers/nvme/host/pci.c
View File

@ -2030,60 +2030,40 @@ static int nvme_setup_host_mem(struct nvme_dev *dev)
return ret; return ret;
} }
static void nvme_calc_io_queues(struct nvme_dev *dev, unsigned int nr_io_queues) static void nvme_calc_io_queues(struct nvme_dev *dev, unsigned int irq_queues)
{ {
unsigned int this_w_queues = write_queues; unsigned int this_w_queues = write_queues;
unsigned int this_p_queues = poll_queues;
/* /*
* Setup read/write queue split * Setup read/write queue split
*/ */
if (nr_io_queues == 1) { if (irq_queues == 1) {
dev->io_queues[HCTX_TYPE_DEFAULT] = 1; dev->io_queues[HCTX_TYPE_DEFAULT] = 1;
dev->io_queues[HCTX_TYPE_READ] = 0; dev->io_queues[HCTX_TYPE_READ] = 0;
dev->io_queues[HCTX_TYPE_POLL] = 0;
return; return;
} }
/*
* Configure number of poll queues, if set
*/
if (this_p_queues) {
/*
* We need at least one queue left. With just one queue, we'll
* have a single shared read/write set.
*/
if (this_p_queues >= nr_io_queues) {
this_w_queues = 0;
this_p_queues = nr_io_queues - 1;
}
dev->io_queues[HCTX_TYPE_POLL] = this_p_queues;
nr_io_queues -= this_p_queues;
} else
dev->io_queues[HCTX_TYPE_POLL] = 0;
/* /*
* If 'write_queues' is set, ensure it leaves room for at least * If 'write_queues' is set, ensure it leaves room for at least
* one read queue * one read queue
*/ */
if (this_w_queues >= nr_io_queues) if (this_w_queues >= irq_queues)
this_w_queues = nr_io_queues - 1; this_w_queues = irq_queues - 1;
/* /*
* If 'write_queues' is set to zero, reads and writes will share * If 'write_queues' is set to zero, reads and writes will share
* a queue set. * a queue set.
*/ */
if (!this_w_queues) { if (!this_w_queues) {
dev->io_queues[HCTX_TYPE_DEFAULT] = nr_io_queues; dev->io_queues[HCTX_TYPE_DEFAULT] = irq_queues;
dev->io_queues[HCTX_TYPE_READ] = 0; dev->io_queues[HCTX_TYPE_READ] = 0;
} else { } else {
dev->io_queues[HCTX_TYPE_DEFAULT] = this_w_queues; dev->io_queues[HCTX_TYPE_DEFAULT] = this_w_queues;
dev->io_queues[HCTX_TYPE_READ] = nr_io_queues - this_w_queues; dev->io_queues[HCTX_TYPE_READ] = irq_queues - this_w_queues;
} }
} }
static int nvme_setup_irqs(struct nvme_dev *dev, int nr_io_queues) static int nvme_setup_irqs(struct nvme_dev *dev, unsigned int nr_io_queues)
{ {
struct pci_dev *pdev = to_pci_dev(dev->dev); struct pci_dev *pdev = to_pci_dev(dev->dev);
int irq_sets[2]; int irq_sets[2];
@ -2093,6 +2073,20 @@ static int nvme_setup_irqs(struct nvme_dev *dev, int nr_io_queues)
.sets = irq_sets, .sets = irq_sets,
}; };
int result = 0; int result = 0;
unsigned int irq_queues, this_p_queues;
/*
* Poll queues don't need interrupts, but we need at least one IO
* queue left over for non-polled IO.
*/
this_p_queues = poll_queues;
if (this_p_queues >= nr_io_queues) {
this_p_queues = nr_io_queues - 1;
irq_queues = 1;
} else {
irq_queues = nr_io_queues - this_p_queues;
}
dev->io_queues[HCTX_TYPE_POLL] = this_p_queues;
/* /*
* For irq sets, we have to ask for minvec == maxvec. This passes * For irq sets, we have to ask for minvec == maxvec. This passes
@ -2100,7 +2094,7 @@ static int nvme_setup_irqs(struct nvme_dev *dev, int nr_io_queues)
* IRQ vector needs. * IRQ vector needs.
*/ */
do { do {
nvme_calc_io_queues(dev, nr_io_queues); nvme_calc_io_queues(dev, irq_queues);
irq_sets[0] = dev->io_queues[HCTX_TYPE_DEFAULT]; irq_sets[0] = dev->io_queues[HCTX_TYPE_DEFAULT];
irq_sets[1] = dev->io_queues[HCTX_TYPE_READ]; irq_sets[1] = dev->io_queues[HCTX_TYPE_READ];
if (!irq_sets[1]) if (!irq_sets[1])
@ -2111,11 +2105,11 @@ static int nvme_setup_irqs(struct nvme_dev *dev, int nr_io_queues)
* 1 + 1 queues, just ask for a single vector. We'll share * 1 + 1 queues, just ask for a single vector. We'll share
* that between the single IO queue and the admin queue. * that between the single IO queue and the admin queue.
*/ */
if (!(result < 0 && nr_io_queues == 1)) if (result >= 0 && irq_queues > 1)
nr_io_queues = irq_sets[0] + irq_sets[1] + 1; irq_queues = irq_sets[0] + irq_sets[1] + 1;
result = pci_alloc_irq_vectors_affinity(pdev, nr_io_queues, result = pci_alloc_irq_vectors_affinity(pdev, irq_queues,
nr_io_queues, irq_queues,
PCI_IRQ_ALL_TYPES | PCI_IRQ_AFFINITY, &affd); PCI_IRQ_ALL_TYPES | PCI_IRQ_AFFINITY, &affd);
/* /*
@ -2125,12 +2119,12 @@ static int nvme_setup_irqs(struct nvme_dev *dev, int nr_io_queues)
* likely does not. Back down to ask for just one vector. * likely does not. Back down to ask for just one vector.
*/ */
if (result == -ENOSPC) { if (result == -ENOSPC) {
nr_io_queues--; irq_queues--;
if (!nr_io_queues) if (!irq_queues)
return result; return result;
continue; continue;
} else if (result == -EINVAL) { } else if (result == -EINVAL) {
nr_io_queues = 1; irq_queues = 1;
continue; continue;
} else if (result <= 0) } else if (result <= 0)
return -EIO; return -EIO;