| Message ID | 20240919121028.1348023-1-0x1207@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net,v2] net: stmmac: set PP_FLAG_DMA_SYNC_DEV only if XDP is enabled | expand |
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index f3a1b179aaea..95d3d1081727 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -2022,7 +2022,7 @@ static int __alloc_dma_rx_desc_resources(struct stmmac_priv *priv, rx_q->queue_index = queue; rx_q->priv_data = priv; - pp_params.flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV; + pp_params.flags = PP_FLAG_DMA_MAP | (xdp_prog ? PP_FLAG_DMA_SYNC_DEV : 0); pp_params.pool_size = dma_conf->dma_rx_size; num_pages = DIV_ROUND_UP(dma_conf->dma_buf_sz, PAGE_SIZE); pp_params.order = ilog2(num_pages);
Commit 5fabb01207a2 ("net: stmmac: Add initial XDP support") sets PP_FLAG_DMA_SYNC_DEV flag for page_pool unconditionally, page_pool_recycle_direct() will call page_pool_dma_sync_for_device() on every page even the page is not going to be reused by XDP program. When XDP is not enabled, the page which holds the received buffer will be recycled once the buffer is copied into new SKB by skb_copy_to_linear_data(), then the MAC core will never reuse this page any longer. Always setting PP_FLAG_DMA_SYNC_DEV wastes CPU cycles on unnecessary calling of page_pool_dma_sync_for_device(). After this patch, up to 9% noticeable performance improvement was observed on certain platforms. Fixes: 5fabb01207a2 ("net: stmmac: Add initial XDP support") Signed-off-by: Furong Xu <0x1207@gmail.com> --- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)