From b97fe3b1aff8195e689b6b07fa5c00e372d2426f Mon Sep 17 00:00:00 2001 From: Emil Tantilov Date: Sat, 8 Nov 2014 01:39:30 +0000 Subject: [PATCH] ixgbevf: Cleanup variable usage, improve stack performance This change is meant to help cleanup the usage of temporary variables within the Rx hot-path by removing unnecessary variables and reducing the scope of variables that do not need to exist outside the main loop. CC: Alexander Duyck Signed-off-by: Emil Tantilov Tested-by: Phil Schmitt Signed-off-by: Jeff Kirsher --- .../net/ethernet/intel/ixgbevf/ixgbevf_main.c | 20 ++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c index 36b005e58930..f864da991c47 100644 --- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c +++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c @@ -517,26 +517,28 @@ static int ixgbevf_clean_rx_irq(struct ixgbevf_q_vector *q_vector, struct ixgbevf_ring *rx_ring, int budget) { - union ixgbe_adv_rx_desc *rx_desc, *next_rxd; - struct ixgbevf_rx_buffer *rx_buffer_info, *next_buffer; - struct sk_buff *skb; + union ixgbe_adv_rx_desc *rx_desc; unsigned int i; unsigned int total_rx_bytes = 0, total_rx_packets = 0; u16 cleaned_count = ixgbevf_desc_unused(rx_ring); i = rx_ring->next_to_clean; rx_desc = IXGBEVF_RX_DESC(rx_ring, i); - rx_buffer_info = &rx_ring->rx_buffer_info[i]; while (ixgbevf_test_staterr(rx_desc, IXGBE_RXD_STAT_DD)) { + union ixgbe_adv_rx_desc *next_rxd; + struct ixgbevf_rx_buffer *rx_buffer_info; + struct sk_buff *skb; + if (!budget) break; budget--; rmb(); /* read descriptor and rx_buffer_info after status DD */ + rx_buffer_info = &rx_ring->rx_buffer_info[i]; skb = rx_buffer_info->skb; - prefetch(skb->data - NET_IP_ALIGN); + prefetch(skb->data); rx_buffer_info->skb = NULL; dma_unmap_single(rx_ring->dev, rx_buffer_info->dma, @@ -545,18 +547,17 @@ static int ixgbevf_clean_rx_irq(struct ixgbevf_q_vector *q_vector, rx_buffer_info->dma = 0; skb_put(skb, le16_to_cpu(rx_desc->wb.upper.length)); + cleaned_count++; + i++; if (i == rx_ring->count) i = 0; next_rxd = IXGBEVF_RX_DESC(rx_ring, i); prefetch(next_rxd); - cleaned_count++; - - next_buffer = &rx_ring->rx_buffer_info[i]; if (!(ixgbevf_test_staterr(rx_desc, IXGBE_RXD_STAT_EOP))) { - skb->next = next_buffer->skb; + skb->next = rx_ring->rx_buffer_info[i].skb; IXGBE_CB(skb->next)->prev = skb; rx_ring->rx_stats.non_eop_descs++; goto next_desc; @@ -609,6 +610,7 @@ next_desc: /* use prefetched values */ rx_desc = next_rxd; rx_buffer_info = &rx_ring->rx_buffer_info[i]; + rx_desc = IXGBEVF_RX_DESC(rx_ring, i); } rx_ring->next_to_clean = i;