From: Matteo Croce mcroce@microsoft.com
mainline inclusion from mainline-v5.14-rc1 commit e4017570daee 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 increased by 10%, from 296 Kpps to 326 Kpps.
perf top on a stock system shows:
Overhead Shared Object Symbol 23.66% [kernel] [k] __pi___inval_dcache_area 22.85% [mvneta] [k] mvneta_rx_swbm 7.54% [kernel] [k] kmem_cache_alloc 6.49% [kernel] [k] eth_type_trans 3.94% [kernel] [k] dev_gro_receive 3.91% [kernel] [k] __netif_receive_skb_core 3.91% [kernel] [k] kmem_cache_free 3.76% [kernel] [k] page_pool_release_page 3.56% [kernel] [k] free_unref_page 2.40% [kernel] [k] build_skb 1.49% [kernel] [k] skb_release_data 1.45% [kernel] [k] __alloc_pages_bulk 1.30% [kernel] [k] page_frag_free
And this is the same output with recycling enabled:
Overhead Shared Object Symbol 26.41% [kernel] [k] __pi___inval_dcache_area 25.00% [mvneta] [k] mvneta_rx_swbm 8.14% [kernel] [k] kmem_cache_alloc 6.84% [kernel] [k] eth_type_trans 4.44% [kernel] [k] __netif_receive_skb_core 4.38% [kernel] [k] kmem_cache_free 4.16% [kernel] [k] dev_gro_receive 3.21% [kernel] [k] page_pool_put_page 2.41% [kernel] [k] build_skb 1.82% [kernel] [k] skb_release_data 1.61% [kernel] [k] napi_gro_receive 1.25% [kernel] [k] page_pool_refill_alloc_cache 1.16% [kernel] [k] __netif_receive_skb_list_core
We can see that page_pool_release_page(), free_unref_page() and __alloc_pages_bulk() are no longer on top of the list when receiving traffic.
The test was done with mausezahn on the TX side with 64 byte raw ethernet frames.
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/mvneta.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c index f7d4f2d6adea..694944e2a4eb 100644 --- a/drivers/net/ethernet/marvell/mvneta.c +++ b/drivers/net/ethernet/marvell/mvneta.c @@ -2303,7 +2303,7 @@ mvneta_swbm_add_rx_fragment(struct mvneta_port *pp, }
static struct sk_buff * -mvneta_swbm_build_skb(struct mvneta_port *pp, struct mvneta_rx_queue *rxq, +mvneta_swbm_build_skb(struct mvneta_port *pp, struct page_pool *pool, struct xdp_buff *xdp, u32 desc_status) { struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp); @@ -2314,7 +2314,7 @@ mvneta_swbm_build_skb(struct mvneta_port *pp, struct mvneta_rx_queue *rxq, if (!skb) return ERR_PTR(-ENOMEM);
- page_pool_release_page(rxq->page_pool, virt_to_page(xdp->data)); + skb_mark_for_recycle(skb, virt_to_page(xdp->data), pool);
skb_reserve(skb, xdp->data - xdp->data_hard_start); skb_put(skb, xdp->data_end - xdp->data); @@ -2326,7 +2326,10 @@ mvneta_swbm_build_skb(struct mvneta_port *pp, struct mvneta_rx_queue *rxq, skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, skb_frag_page(frag), skb_frag_off(frag), skb_frag_size(frag), PAGE_SIZE); - page_pool_release_page(rxq->page_pool, skb_frag_page(frag)); + /* We don't need to reset pp_recycle here. It's already set, so + * just mark fragments for recycling. + */ + page_pool_store_mem_info(skb_frag_page(frag), pool); }
return skb; @@ -2405,7 +2408,7 @@ static int mvneta_rx_swbm(struct napi_struct *napi, mvneta_run_xdp(pp, rxq, xdp_prog, &xdp_buf, frame_sz, &ps)) goto next;
- skb = mvneta_swbm_build_skb(pp, rxq, &xdp_buf, desc_status); + skb = mvneta_swbm_build_skb(pp, rxq->page_pool, &xdp_buf, desc_status); if (IS_ERR(skb)) { struct mvneta_pcpu_stats *stats = this_cpu_ptr(pp->stats);