Commit 90987650 authored May 15, 2022 by Eric Dumazet Committed by David S. Miller May 16, 2022

net: call skb_defer_free_flush() before each napi_poll()



skb_defer_free_flush() can consume cpu cycles,
it seems better to call it in the inner loop:

- Potentially frees page/skb that will be reallocated while hot.

- Account for the cpu cycles in the @time_limit determination.

- Keep softnet_data.defer_count small to reduce chances for
  skb_attempt_defer_free() to send an IPI.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 39564c3f

net/core/dev.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -6655,6 +6655,8 @@ static __latent_entropy void net_rx_action(struct softirq_action *h)
		for (;;) {
		struct napi_struct *n;

		skb_defer_free_flush(sd);

		if (list_empty(&list)) {
		if (!sd_has_rps_ipi_waiting(sd) && list_empty(&repoll))
		goto end;
		@@ -6684,8 +6686,7 @@ static __latent_entropy void net_rx_action(struct softirq_action *h)
		__raise_softirq_irqoff(NET_RX_SOFTIRQ);

		net_rps_action_and_irq_enable(sd);
		end:
		skb_defer_free_flush(sd);
		end:;
		}

		struct netdev_adjacent {