On 16-11-15 10:15 AM, Eric Dumazet wrote: > It is time to have preemption points in sk_busy_loop() and improve > its scalability. > > Also napi_complete() and friends can tell drivers when it is safe to > not re-enable device interrupts, saving some overhead under > high busy polling. > > mlx4 and bnx2x are changed accordingly, to show how this busy polling > status can be exploited by drivers. > > Next steps will implement Zach Brown suggestion, where NAPI polling > would be enabled all the time for some chosen queues. > This is needed for efficient epoll() support anyway.
Would you expect to make this a per queue option of the hardware configured via ethtool/netlink/sysfs and like where users steer traffic to particular queues using existing ntuple filters or 'tc' or infer it from the socket layer? So configuration would be (a) enable busy-polling on queues x,y,z and then (b) use ntuple/RSS/etc to steer relative traffic to queues. In this case traffic doesn't need to be bound to a socket in any way. Seems like a useful generalization. Thanks, John > > Eric Dumazet (5): > net: busy-poll: allow preemption in sk_busy_loop() > net: busy-poll: remove need_resched() from sk_can_busy_loop() > net: busy-poll: return busypolling status to drivers > net/mlx4_en: use napi_complete_done() return value > bnx2x: switch to napi_complete_done() > > drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | 15 ++-- > drivers/net/ethernet/mellanox/mlx4/en_rx.c | 4 +- > include/linux/netdevice.h | 17 +++- > include/net/busy_poll.h | 5 +- > net/core/dev.c | 110 > +++++++++++++++++++----- > 5 files changed, 113 insertions(+), 38 deletions(-) >
