* [PATCH] nvme-pci: No IRQ map for read if no read queue allocated
@ 2019-07-08 17:24 Alan Mikhak
2019-07-09 21:22 ` Christoph Hellwig
0 siblings, 1 reply; 2+ messages in thread
From: Alan Mikhak @ 2019-07-08 17:24 UTC (permalink / raw)
To: linux-nvme, linux-kernel, kbusch, axboe, hch, sagi, palmer,
paul.walmsley
Cc: Alan Mikhak
From: Alan Mikhak <alan.mikhak@sifive.com>
nvme_dev_add() assumes a read queue is always allocated.
That may not be the case on single-interrupt systems for
which pci_assign_irq() would report runtime IRQ mapping
not provided by arch.
This patch makes sure nvme_dev_add() only requests an
IRQ mapping for read queues if at least one read queue
is being allocted.
nvme_pci_map_queues() will later on ignore the unnecessary
mapping request should nvme_dev_add() request such an IRQ
mapping even though no read queues are being allocated.
However, nvme_dev_add() can avoid making the request by
checking the number of read queues without assuming. This
would bring it more in line with nvme_setup_irqs() and
nvme_calc_irq_sets().
Signed-off-by: Alan Mikhak <alan.mikhak@sifive.com>
---
drivers/nvme/host/pci.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 524d6bd6d095..86262ebe6fff 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2263,7 +2263,9 @@ static int nvme_dev_add(struct nvme_dev *dev)
if (!dev->ctrl.tagset) {
dev->tagset.ops = &nvme_mq_ops;
dev->tagset.nr_hw_queues = dev->online_queues - 1;
- dev->tagset.nr_maps = 2; /* default + read */
+ dev->tagset.nr_maps = 1; /* default */
+ if (dev->io_queues[HCTX_TYPE_READ])
+ dev->tagset.nr_maps++;
if (dev->io_queues[HCTX_TYPE_POLL])
dev->tagset.nr_maps++;
dev->tagset.timeout = NVME_IO_TIMEOUT;
--
2.7.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] nvme-pci: No IRQ map for read if no read queue allocated
2019-07-08 17:24 [PATCH] nvme-pci: No IRQ map for read if no read queue allocated Alan Mikhak
@ 2019-07-09 21:22 ` Christoph Hellwig
0 siblings, 0 replies; 2+ messages in thread
From: Christoph Hellwig @ 2019-07-09 21:22 UTC (permalink / raw)
To: Alan Mikhak
Cc: linux-nvme, linux-kernel, kbusch, axboe, hch, sagi, palmer,
paul.walmsley
Thanks,
applied to nvme-5.3 with a little massaging of the commit log.
^ permalink raw reply [flat|nested] 2+ messages in thread
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