From: Matteo Croce mcroce@microsoft.com
mainline inclusion from mainline-v5.14-rc1 commit 133637fcfab2 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I4CVS3 CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Use the new recycling API for page_pool. In a drop rate test, the packet rate is almost doubled, from 1110 Kpps to 2128 Kpps.
perf top on a stock system shows:
Overhead Shared Object Symbol 34.88% [kernel] [k] page_pool_release_page 8.06% [kernel] [k] free_unref_page 6.42% [mvpp2] [k] mvpp2_rx 6.07% [kernel] [k] eth_type_trans 5.18% [kernel] [k] __netif_receive_skb_core 4.95% [kernel] [k] build_skb 4.88% [kernel] [k] kmem_cache_free 3.97% [kernel] [k] kmem_cache_alloc 3.45% [kernel] [k] dev_gro_receive 2.73% [kernel] [k] page_frag_free 2.07% [kernel] [k] __alloc_pages_bulk 1.99% [kernel] [k] arch_local_irq_save 1.84% [kernel] [k] skb_release_data 1.20% [kernel] [k] netif_receive_skb_list_internal
With packet rate stable at 1100 Kpps:
tx: 0 bps 0 pps rx: 532.7 Mbps 1110 Kpps tx: 0 bps 0 pps rx: 532.6 Mbps 1110 Kpps tx: 0 bps 0 pps rx: 532.4 Mbps 1109 Kpps tx: 0 bps 0 pps rx: 532.1 Mbps 1109 Kpps tx: 0 bps 0 pps rx: 531.9 Mbps 1108 Kpps tx: 0 bps 0 pps rx: 531.9 Mbps 1108 Kpps
And this is the same output with recycling enabled:
Overhead Shared Object Symbol 12.91% [kernel] [k] eth_type_trans 12.54% [mvpp2] [k] mvpp2_rx 9.67% [kernel] [k] build_skb 9.63% [kernel] [k] __netif_receive_skb_core 8.44% [kernel] [k] page_pool_put_page 8.07% [kernel] [k] kmem_cache_free 7.79% [kernel] [k] kmem_cache_alloc 6.86% [kernel] [k] dev_gro_receive 3.19% [kernel] [k] skb_release_data 2.41% [kernel] [k] netif_receive_skb_list_internal 2.18% [kernel] [k] page_pool_refill_alloc_cache 1.76% [kernel] [k] napi_gro_receive 1.61% [kernel] [k] kfree_skb 1.20% [kernel] [k] dma_sync_single_for_device 1.16% [mvpp2] [k] mvpp2_poll 1.12% [mvpp2] [k] mvpp2_read
With packet rate above 2100 Kpps:
tx: 0 bps 0 pps rx: 1021 Mbps 2128 Kpps tx: 0 bps 0 pps rx: 1021 Mbps 2127 Kpps tx: 0 bps 0 pps rx: 1021 Mbps 2128 Kpps tx: 0 bps 0 pps rx: 1021 Mbps 2128 Kpps tx: 0 bps 0 pps rx: 1022 Mbps 2128 Kpps tx: 0 bps 0 pps rx: 1022 Mbps 2129 Kpps
The major performance increase is explained by the fact that the most CPU consuming functions (page_pool_release_page, page_frag_free and free_unref_page) are no longer called on a per packet basis.
The test was done by sending to the macchiatobin 64 byte ethernet frames with an invalid ethertype, so the packets are dropped early in the RX path.
Signed-off-by: Matteo Croce mcroce@microsoft.com Signed-off-by: David S. Miller davem@davemloft.net Reviewed-by: Yongxin Li liyongxin1@huawei.com Signed-off-by: Junxin Chen chenjunxin1@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c index bafdf287c478..e4360b1803bf 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c @@ -3639,7 +3639,7 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, }
if (pp) - page_pool_release_page(pp, virt_to_page(data)); + skb_mark_for_recycle(skb, virt_to_page(data), pp); else dma_unmap_single_attrs(dev->dev.parent, dma_addr, bm_pool->buf_size, DMA_FROM_DEVICE,