Subject: Re: [RFC net-next (v2) 12/14] ixgbe: set maximal number of default RSS queues

From: Alexander Duyck <[email-masked]>
Date: Mon, 25 Jun 2012 11:38:17 -0700

On 06/25/2012 10:53 AM, Eilon Greenstein wrote:
> On Mon, 2012-06-25 at 08:44 -0700, Alexander Duyck wrote:
>> This doesn't limit queues, only interrupt vectors.  As I told you before
>> you should look at the ixgbe_set_rss_queues function if you actually
>> want to limit the number of RSS queues.
> How about this:
> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c
> index af1a531..23a8609 100644
> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c
> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c
> @@ -277,6 +277,8 @@ static inline bool ixgbe_set_rss_queues(struct ixgbe_adapter *adapter)
>  	bool ret = false;
>  	struct ixgbe_ring_feature *f = &adapter->ring_feature[RING_F_RSS];
>  
> +	f->indices = min_t(int, netif_get_num_default_rss_queues(), f->indices);
> +
>  	if (adapter->flags & IXGBE_FLAG_RSS_ENABLED) {
>  		f->mask = 0xF;
>  		adapter->num_rx_queues = f->indices;
> @@ -302,7 +304,9 @@ static inline bool ixgbe_set_fdir_queues(struct ixgbe_adapter *adapter)
>  	bool ret = false;
>  	struct ixgbe_ring_feature *f_fdir = &adapter->ring_feature[RING_F_FDIR];
>  
> -	f_fdir->indices = min_t(int, num_online_cpus(), f_fdir->indices);
> +	f_fdir->indices = min_t(int, netif_get_num_default_rss_queues(),
> +				f_fdir->indices);
> +
>  	f_fdir->mask = 0;
>  
>  	/*
> @@ -339,8 +343,7 @@ static inline bool ixgbe_set_fcoe_queues(struct ixgbe_adapter *adapter)
>  	if (!(adapter->flags & IXGBE_FLAG_FCOE_ENABLED))
>  		return false;
>  
> -	f->indices = min_t(int, num_online_cpus(), f->indices);
> -
> +	f->indices = min_t(int, f->indices, netif_get_num_default_rss_queues());
>  	adapter->num_rx_queues = 1;
>  	adapter->num_tx_queues = 1;
>
This makes much more sense, but still needs a few minor changes.  The
first change I would recommend is to not alter ixgbe_set_fdir_queues
since that controls flow director queues, not RSS queues.  The second
would be to update ixgbe_set_dcb_queues since that does RSS per DCB
traffic class and will also need to be updated.

Thanks,

Alex