Commit 87eff2ec authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: optimize napi_threaded_poll() vs RPS/RFS 



We use napi_threaded_poll() in order to reduce our softirq dependency.

We can add a followup of 821eba96 ("net: optimize napi_schedule_rps()")
to further remove the need of firing NET_RX_SOFTIRQ whenever
RPS/RFS are used.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Acked-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a1aaee7f

include/linux/netdevice.h

+3 −0
Original line number Diff line number Diff line
@@ -3194,7 +3194,10 @@ struct softnet_data { 
#ifdef CONFIG_RPS

	struct softnet_data	*rps_ipi_list;

#endif



	bool			in_net_rx_action;

	bool			in_napi_threaded_poll;



#ifdef CONFIG_NET_FLOW_LIMIT

	struct sd_flow_limit __rcu *flow_limit;

#endif

net/core/dev.c

+10 −2
Original line number Diff line number Diff line
@@ -4603,10 +4603,10 @@ static void napi_schedule_rps(struct softnet_data *sd) 
		sd->rps_ipi_next = mysd->rps_ipi_list;

		mysd->rps_ipi_list = sd;



		/* If not called from net_rx_action()

		/* If not called from net_rx_action() or napi_threaded_poll()

		 * we have to raise NET_RX_SOFTIRQ.

		 */

		if (!mysd->in_net_rx_action)

		if (!mysd->in_net_rx_action && !mysd->in_napi_threaded_poll)

			__raise_softirq_irqoff(NET_RX_SOFTIRQ);

		return;

	}
@@ -6631,11 +6631,19 @@ static int napi_threaded_poll(void *data) 


			local_bh_disable();

			sd = this_cpu_ptr(&softnet_data);

			sd->in_napi_threaded_poll = true;



			have = netpoll_poll_lock(napi);

			__napi_poll(napi, &repoll);

			netpoll_poll_unlock(have);



			sd->in_napi_threaded_poll = false;

			barrier();



			if (sd_has_rps_ipi_waiting(sd)) {

				local_irq_disable();

				net_rps_action_and_irq_enable(sd);

			}

			skb_defer_free_flush(sd);

			local_bh_enable();