Re: [PATCH] ixgbe: take online CPU number as MQ max limit when alloc_etherdev_mq()

[Sergei Shtylyov]

Hello.

On 5/13/2016 8:56 AM, Ethan Zhao wrote:

> Allocating 64 Tx/Rx as default doesn't benefit perfomrnace when less

   Performance.

> CPUs were assigned. especially when DCB is enabled, so we should take
> num_online_cpus() as top limit, and aslo to make sure every TC has

   Also.

> at least one queue, take the MAX_TRAFFIC_CLASS as bottom limit of queues
> number.
>
> Signed-off-by: Ethan Zhao <ethan.zhao@xxxxxxxxxx>
> ---
>  drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> index 7df3fe2..1f9769c 100644
> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> @@ -9105,6 +9105,10 @@ static int ixgbe_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>  		indices = IXGBE_MAX_RSS_INDICES;
>  #endif
>  	}
> +	/* Don't allocate too more queues than online cpus number */

   "Too" not needed here. CPUs.

> +	indices = min_t(int, indices, num_online_cpus());
> +	/* To make sure TC works, allocate at least 1 queue per TC */
> +	indices = max_t(int, indices, MAX_TRAFFIC_CLASS);
>
>  	netdev = alloc_etherdev_mq(sizeof(struct ixgbe_adapter), indices);
>  	if (!netdev) {

MBR, Sergei