The 04/20/2023 22:52, Maciej Fijalkowski wrote: > [Some people who received this message don't often get email from maciej.fijalkowski@xxxxxxxxx. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ] > Hi Maciej, > > On Thu, Apr 20, 2023 at 02:11:52PM +0200, Horatiu Vultur wrote: > > 'net: ' in patch subject is excessive to me I usually have set this in the subject. I can remove this in the next version and I will try to keep in mind for other patches for lan966x. > > > When the action of an xdp program was XDP_TX, lan966x was creating > > a xdp_frame and use this one to send the frame back. But it is also > > possible to send back the frame without needing a xdp_frame, because > > it possible to send it back using the page. > > s/it/it is > > > And then once the frame is transmitted is possible to use directly > > page_pool_recycle_direct as lan966x is using page pools. > > This would save some CPU usage on this path. > > i remember this optimization gave me noticeable perf improvement, would > you mind sharing it in % on your side? The way I have done the measurements, is to measure actually how much more traffic can be send back. I tried with different frame sizes, frame size improvement 64 ~8% 256 ~11% 512 ~8% 1000 ~0% 1500 ~0% I will make sure do add this to the comments in the next version. > > > > > Signed-off-by: Horatiu Vultur <horatiu.vultur@xxxxxxxxxxxxx> > > --- > > .../ethernet/microchip/lan966x/lan966x_fdma.c | 35 +++++++++++-------- > > .../ethernet/microchip/lan966x/lan966x_main.h | 2 ++ > > .../ethernet/microchip/lan966x/lan966x_xdp.c | 11 +++--- > > 3 files changed, 27 insertions(+), 21 deletions(-) > > > > diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c > > index 2ed76bb61a731..7947259e67e4e 100644 > > --- a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c > > +++ b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c > > @@ -390,6 +390,7 @@ static void lan966x_fdma_stop_netdev(struct lan966x *lan966x) > > static void lan966x_fdma_tx_clear_buf(struct lan966x *lan966x, int weight) > > { > > struct lan966x_tx *tx = &lan966x->tx; > > + struct lan966x_rx *rx = &lan966x->rx; > > struct lan966x_tx_dcb_buf *dcb_buf; > > struct xdp_frame_bulk bq; > > struct lan966x_db *db; > > @@ -432,7 +433,8 @@ static void lan966x_fdma_tx_clear_buf(struct lan966x *lan966x, int weight) > > if (dcb_buf->xdp_ndo) > > xdp_return_frame_bulk(dcb_buf->data.xdpf, &bq); > > else > > - xdp_return_frame_rx_napi(dcb_buf->data.xdpf); > > + page_pool_recycle_direct(rx->page_pool, > > + dcb_buf->data.page); > > } > > > > clear = true; > > @@ -702,6 +704,7 @@ static void lan966x_fdma_tx_start(struct lan966x_tx *tx, int next_to_use) > > int lan966x_fdma_xmit_xdpf(struct lan966x_port *port, > > struct xdp_frame *xdpf, > > struct page *page, > > + u32 len, > > agreed with Olek regarding arguments reduction here Yes, I will change this in the next version. > > > bool dma_map) > > { > > struct lan966x *lan966x = port->lan966x; > > @@ -722,6 +725,15 @@ int lan966x_fdma_xmit_xdpf(struct lan966x_port *port, > > goto out; > > } > > > > + /* Fill up the buffer */ > > + next_dcb_buf = &tx->dcbs_buf[next_to_use]; > > + next_dcb_buf->use_skb = false; > > + next_dcb_buf->xdp_ndo = dma_map; > > a bit misleading that xdp_ndo is a bool :P There are few other variables that are misleading :), I need to get to this and clean it a little bit. > > > + next_dcb_buf->len = len + IFH_LEN_BYTES; > > + next_dcb_buf->used = true; > > + next_dcb_buf->ptp = false; > > + next_dcb_buf->dev = port->dev; > > + > > /* Generate new IFH */ > > if (dma_map) { > > if (xdpf->headroom < IFH_LEN_BYTES) { -- /Horatiu
