On Wed, 3 Jul 2019 12:37:50 +0200 Jose Abreu <jose.ab...@synopsys.com> wrote:
> @@ -3547,6 +3456,9 @@ static int stmmac_rx(struct stmmac_priv *priv, int > limit, u32 queue) > > napi_gro_receive(&ch->rx_napi, skb); > > + page_pool_recycle_direct(rx_q->page_pool, buf->page); This doesn't look correct. The page_pool DMA mapping cannot be "kept" when page traveling into the network stack attached to an SKB. (Ilias and I have a long term plan[1] to allow this, but you cannot do it ATM). You will have to call: page_pool_release_page(rx_q->page_pool, buf->page); This will do a DMA-unmap, and you will likely loose your performance gain :-( > + buf->page = NULL; > + > priv->dev->stats.rx_packets++; > priv->dev->stats.rx_bytes += frame_len; > } Also remember that the page_pool requires you driver to do the DMA-sync operation. I see a dma_sync_single_for_cpu(), but I didn't see a dma_sync_single_for_device() (well, I noticed one getting removed). (For some HW Ilias tells me that the dma_sync_single_for_device can be elided, so maybe this can still be correct for you). [1] https://github.com/xdp-project/xdp-project/blob/master/areas/mem/page_pool02_SKB_return_callback.org -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer
