[PATCH AUTOSEL 5.4 13/52] nvme/pci: Fix read queue count

From: Sasha Levin
Date: Fri Dec 20 2019 - 09:30:18 EST


From: Keith Busch <kbusch@xxxxxxxxxx>

[ Upstream commit 7e4c6b9a5d22485acf009b3c3510a370f096dd54 ]

If nvme.write_queues equals the number of CPUs, the driver had decreased
the number of interrupts available such that there could only be one read
queue even if the controller could support more. Remove the interrupt
count reduction in this case. The driver wouldn't request more IRQs than
it wants queues anyway.

Reviewed-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Keith Busch <kbusch@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/nvme/host/pci.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 29d7427c2b19b..14d513087a14b 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2060,7 +2060,6 @@ static int nvme_setup_irqs(struct nvme_dev *dev, unsigned int nr_io_queues)
.priv = dev,
};
unsigned int irq_queues, this_p_queues;
- unsigned int nr_cpus = num_possible_cpus();

/*
* Poll queues don't need interrupts, but we need at least one IO
@@ -2071,10 +2070,7 @@ static int nvme_setup_irqs(struct nvme_dev *dev, unsigned int nr_io_queues)
this_p_queues = nr_io_queues - 1;
irq_queues = 1;
} else {
- if (nr_cpus < nr_io_queues - this_p_queues)
- irq_queues = nr_cpus + 1;
- else
- irq_queues = nr_io_queues - this_p_queues + 1;
+ irq_queues = nr_io_queues - this_p_queues + 1;
}
dev->io_queues[HCTX_TYPE_POLL] = this_p_queues;

--
2.20.1