Re: [PATCH 3/3] nvme/pci: Fix read queue count

[Ming Lei <tom.leiming@gmail.com>]

On 12/7/19, Keith Busch <kbusch@kernel.org> wrote:
> If nvme.write_queues and poll_queues are specified, we expect the driver
> may request more queues than CPUs if the device's queue count feature
> is large enough. The driver, however, had been decreasing the number of
> possible interrupt enabled queues, artifically limiting the number of
> read queues even if the controller could support more.
>
> The driver doesn't request more IO queues than CPUs for each queues type
> anyway, so remove the cpu count comparison to the number of interrupt
> enabled io queues.
>
> Signed-off-by: Keith Busch <kbusch@kernel.org>
> ---
>  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 6b6452486155..d3bed5df9ef1 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -2062,7 +2062,6 @@ 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
> @@ -2073,10 +2072,7 @@ 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;
>
> --
> 2.21.0

Fixes: dad77d63903e("nvme-pci: adjust irq max_vector using num_possible_cpus()")


Thanks,
Ming Lei

_______________________________________________
linux-nvme mailing list
linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme