On Tue, 3 Apr 2018 17:20:49 -0700, Eric Dumazet wrote: > On 04/03/2018 05:14 PM, Jakub Kicinski wrote: > > Some popular NIC vendors are not adhering to > > netif_get_num_default_rss_queues() which leads to users being > > surprised and filing bugs :) Bump the number of default RX > > queues to something more reasonable for modern machines. > > > > Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com> > > --- > > I'm mostly wondering what's the policy on this default? When > > should it be applied? Why was 8 chosen as the default? We > > can abandon using netif_get_num_default_rss_queues() for the > > nfp but I wonder what's the correct course of action here... > > Should new drivers use netif_get_num_default_rss_queues() for > > example? > > > > include/linux/netdevice.h | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h > > index 2a2d9cf50aa2..26fe145ada2a 100644 > > --- a/include/linux/netdevice.h > > +++ b/include/linux/netdevice.h > > @@ -3260,7 +3260,7 @@ static inline unsigned int get_netdev_rx_queue_index( > > } > > #endif > > > > -#define DEFAULT_MAX_NUM_RSS_QUEUES (8) > > +#define DEFAULT_MAX_NUM_RSS_QUEUES (64) > > int netif_get_num_default_rss_queues(void); > > There is no evidence having so many queues is beneficial. > > Too many queues -> lots of overhead in many cases. > > So I would rather not touch this, unless you can present good numbers ;)
Thank you for the comment! I don't have convincing number it was more of a matter of consistency :) Now I think I forgot about aRFS, when aRFS support for the nfp is added we will probably start ignoring the default as well.
