From 5e040d4b1a440b832c7b4cf8116eebcdff91909c Mon Sep 17 00:00:00 2001 From: Edward Cree Date: Tue, 6 Aug 2019 14:53:20 +0100 Subject: [PATCH] sfc: don't score irq moderation points for GRO We already scored points when handling the RX event, no-one else does this, and looking at the history it appears this was originally meant to only score on merges, not on GRO_NORMAL. Moreover, it gets in the way of changing GRO to not immediately pass GRO_NORMAL skbs to the stack. Performance testing with four TCP streams received on a single CPU (where throughput was line rate of 9.4Gbps in all tests) showed a 13.7% reduction in RX CPU usage (n=6, p=0.03). Signed-off-by: Edward Cree Signed-off-by: David S. Miller --- drivers/net/ethernet/sfc/rx.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c index d5db045535d3..85ec07f5a674 100644 --- a/drivers/net/ethernet/sfc/rx.c +++ b/drivers/net/ethernet/sfc/rx.c @@ -412,7 +412,6 @@ efx_rx_packet_gro(struct efx_channel *channel, struct efx_rx_buffer *rx_buf, unsigned int n_frags, u8 *eh) { struct napi_struct *napi = &channel->napi_str; - gro_result_t gro_result; struct efx_nic *efx = channel->efx; struct sk_buff *skb; @@ -449,9 +448,7 @@ efx_rx_packet_gro(struct efx_channel *channel, struct efx_rx_buffer *rx_buf, skb_record_rx_queue(skb, channel->rx_queue.core_index); - gro_result = napi_gro_frags(napi); - if (gro_result != GRO_DROP) - channel->irq_mod_score += 2; + napi_gro_frags(napi); } /* Allocate and construct an SKB around page fragments */ -- 2.11.0