From 2f128eb3308a74ef478286b75e26aa6d0ed3c6a6 Mon Sep 17 00:00:00 2001 From: Matteo Croce Date: Wed, 9 Jun 2021 15:47:14 +0200 Subject: [PATCH] mvpp2: prefetch page MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Most of the time during the RX is caused by the compound_head() call done at the end of the RX loop: │ build_skb(): [...] │ static inline struct page *compound_head(struct page *page) │ { │ unsigned long head = READ_ONCE(page->compound_head); 65.23 │ ldr x2, [x1, #8] Prefetch the page struct as soon as possible, to speedup the RX path noticeabily by a ~3-4% packet rate in a drop test. │ build_skb(): [...] │ static inline struct page *compound_head(struct page *page) │ { │ unsigned long head = READ_ONCE(page->compound_head); 17.92 │ ldr x2, [x1, #8] Signed-off-by: Matteo Croce Signed-off-by: David S. Miller --- drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c index 07d8f3e31b52..9bca8c8f9f8d 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c @@ -3900,15 +3900,19 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, phys_addr_t phys_addr; u32 rx_status, timestamp; int pool, rx_bytes, err, ret; + struct page *page; void *data; + phys_addr = mvpp2_rxdesc_cookie_get(port, rx_desc); + data = (void *)phys_to_virt(phys_addr); + page = virt_to_page(data); + prefetch(page); + rx_done++; rx_status = mvpp2_rxdesc_status_get(port, rx_desc); rx_bytes = mvpp2_rxdesc_size_get(port, rx_desc); rx_bytes -= MVPP2_MH_SIZE; dma_addr = mvpp2_rxdesc_dma_addr_get(port, rx_desc); - phys_addr = mvpp2_rxdesc_cookie_get(port, rx_desc); - data = (void *)phys_to_virt(phys_addr); pool = (rx_status & MVPP2_RXD_BM_POOL_ID_MASK) >> MVPP2_RXD_BM_POOL_ID_OFFS; @@ -3997,7 +4001,7 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, } if (pp) - skb_mark_for_recycle(skb, virt_to_page(data), pp); + skb_mark_for_recycle(skb, page, pp); else dma_unmap_single_attrs(dev->dev.parent, dma_addr, bm_pool->buf_size, DMA_FROM_DEVICE, -- 2.20.1