| Message ID | 20230421131422.3530159-1-horatiu.vultur@microchip.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next,v2] lan966x: Don't use xdp_frame when action is XDP_TX | expand |
From: Horatiu Vultur <horatiu.vultur@microchip.com> Date: Fri, 21 Apr 2023 15:14:22 +0200 > 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 is possible to send it back using the page. > 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, which results in higher > number of transmitted frames. Bellow are the statistics: > Frame size: Improvement: > 64 ~8% > 256 ~11% > 512 ~8% Nice bump, esp. for 256 }:> > 1000 ~0% > 1500 ~0% [...] > @@ -699,15 +701,14 @@ static void lan966x_fdma_tx_start(struct lan966x_tx *tx, int next_to_use) > tx->last_in_use = next_to_use; > } > > -int lan966x_fdma_xmit_xdpf(struct lan966x_port *port, > - struct xdp_frame *xdpf, > - struct page *page, > - bool dma_map) > +int lan966x_fdma_xmit_xdpf(struct lan966x_port *port, void *ptr, u32 len) > { > struct lan966x *lan966x = port->lan966x; > struct lan966x_tx_dcb_buf *next_dcb_buf; > struct lan966x_tx *tx = &lan966x->tx; > + struct xdp_frame *xdpf; > dma_addr_t dma_addr; > + struct page *page; > int next_to_use; > __be32 *ifh; > int ret = 0; > @@ -722,8 +723,19 @@ 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 = !len; > + next_dcb_buf->len = len + IFH_LEN_BYTES; Is it intended that for .ndo_xdp_xmit cases this field will equal just %IFH_LEN_BYTES as @len is zero? > + next_dcb_buf->used = true; > + next_dcb_buf->ptp = false; > + next_dcb_buf->dev = port->dev; > + > /* Generate new IFH */ > - if (dma_map) { > + if (!len) { > + xdpf = ptr; > + > if (xdpf->headroom < IFH_LEN_BYTES) { > ret = NETDEV_TX_OK; > goto out; [...] Thanks, Olek
The 04/21/2023 15:34, Alexander Lobakin wrote: > > From: Horatiu Vultur <horatiu.vultur@microchip.com> > Date: Fri, 21 Apr 2023 15:14:22 +0200 > > [...] > > > @@ -699,15 +701,14 @@ static void lan966x_fdma_tx_start(struct lan966x_tx *tx, int next_to_use) > > tx->last_in_use = next_to_use; > > } > > > > -int lan966x_fdma_xmit_xdpf(struct lan966x_port *port, > > - struct xdp_frame *xdpf, > > - struct page *page, > > - bool dma_map) > > +int lan966x_fdma_xmit_xdpf(struct lan966x_port *port, void *ptr, u32 len) > > { > > struct lan966x *lan966x = port->lan966x; > > struct lan966x_tx_dcb_buf *next_dcb_buf; > > struct lan966x_tx *tx = &lan966x->tx; > > + struct xdp_frame *xdpf; > > dma_addr_t dma_addr; > > + struct page *page; > > int next_to_use; > > __be32 *ifh; > > int ret = 0; > > @@ -722,8 +723,19 @@ 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 = !len; > > + next_dcb_buf->len = len + IFH_LEN_BYTES; > > Is it intended that for .ndo_xdp_xmit cases this field will equal just > %IFH_LEN_BYTES as @len is zero? Argh, no it is a mistake. For that case it should be xdpf->len + IFH_LEN_BYTES. As I focus on the XDP_TX, I fogot to test also XDP_REDIRECT. :( Thanks for the good catch! I will fix this in the next version. > > > + next_dcb_buf->used = true; > > + next_dcb_buf->ptp = false; > > + next_dcb_buf->dev = port->dev; > > + > > /* Generate new IFH */ > > - if (dma_map) { > > + if (!len) { > > + xdpf = ptr; > > + > > if (xdpf->headroom < IFH_LEN_BYTES) { > > ret = NETDEV_TX_OK; > > goto out; > [...] > > Thanks, > Olek
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c index 2ed76bb61a731..85c13231e0176 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; @@ -699,15 +701,14 @@ static void lan966x_fdma_tx_start(struct lan966x_tx *tx, int next_to_use) tx->last_in_use = next_to_use; } -int lan966x_fdma_xmit_xdpf(struct lan966x_port *port, - struct xdp_frame *xdpf, - struct page *page, - bool dma_map) +int lan966x_fdma_xmit_xdpf(struct lan966x_port *port, void *ptr, u32 len) { struct lan966x *lan966x = port->lan966x; struct lan966x_tx_dcb_buf *next_dcb_buf; struct lan966x_tx *tx = &lan966x->tx; + struct xdp_frame *xdpf; dma_addr_t dma_addr; + struct page *page; int next_to_use; __be32 *ifh; int ret = 0; @@ -722,8 +723,19 @@ 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 = !len; + 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 (!len) { + xdpf = ptr; + if (xdpf->headroom < IFH_LEN_BYTES) { ret = NETDEV_TX_OK; goto out; @@ -743,11 +755,15 @@ int lan966x_fdma_xmit_xdpf(struct lan966x_port *port, goto out; } + next_dcb_buf->data.xdpf = xdpf; + /* Setup next dcb */ lan966x_fdma_tx_setup_dcb(tx, next_to_use, xdpf->len + IFH_LEN_BYTES, dma_addr); } else { + page = ptr; + ifh = page_address(page) + XDP_PACKET_HEADROOM; memset(ifh, 0x0, sizeof(__be32) * IFH_LEN); lan966x_ifh_set_bypass(ifh, 1); @@ -756,25 +772,18 @@ int lan966x_fdma_xmit_xdpf(struct lan966x_port *port, dma_addr = page_pool_get_dma_addr(page); dma_sync_single_for_device(lan966x->dev, dma_addr + XDP_PACKET_HEADROOM, - xdpf->len + IFH_LEN_BYTES, + len + IFH_LEN_BYTES, DMA_TO_DEVICE); + next_dcb_buf->data.page = page; + /* Setup next dcb */ lan966x_fdma_tx_setup_dcb(tx, next_to_use, - xdpf->len + IFH_LEN_BYTES, + len + IFH_LEN_BYTES, dma_addr + XDP_PACKET_HEADROOM); } - /* Fill up the buffer */ - next_dcb_buf = &tx->dcbs_buf[next_to_use]; - next_dcb_buf->use_skb = false; - next_dcb_buf->data.xdpf = xdpf; - next_dcb_buf->xdp_ndo = dma_map; - next_dcb_buf->len = xdpf->len + IFH_LEN_BYTES; next_dcb_buf->dma_addr = dma_addr; - next_dcb_buf->used = true; - next_dcb_buf->ptp = false; - next_dcb_buf->dev = port->dev; /* Start the transmission */ lan966x_fdma_tx_start(tx, next_to_use); diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h index 757378516f1fd..27f272831ea5c 100644 --- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h +++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h @@ -262,6 +262,7 @@ struct lan966x_tx_dcb_buf { union { struct sk_buff *skb; struct xdp_frame *xdpf; + struct page *page; } data; u32 len; u32 used : 1; @@ -593,10 +594,7 @@ int lan966x_ptp_setup_traps(struct lan966x_port *port, struct ifreq *ifr); int lan966x_ptp_del_traps(struct lan966x_port *port); int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev); -int lan966x_fdma_xmit_xdpf(struct lan966x_port *port, - struct xdp_frame *frame, - struct page *page, - bool dma_map); +int lan966x_fdma_xmit_xdpf(struct lan966x_port *port, void *ptr, u32 len); int lan966x_fdma_change_mtu(struct lan966x *lan966x); void lan966x_fdma_netdev_init(struct lan966x *lan966x, struct net_device *dev); void lan966x_fdma_netdev_deinit(struct lan966x *lan966x, struct net_device *dev); diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c b/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c index 2e6f486ec67d7..9ee61db8690b4 100644 --- a/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c +++ b/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c @@ -62,7 +62,7 @@ int lan966x_xdp_xmit(struct net_device *dev, struct xdp_frame *xdpf = frames[i]; int err; - err = lan966x_fdma_xmit_xdpf(port, xdpf, NULL, true); + err = lan966x_fdma_xmit_xdpf(port, xdpf, 0); if (err) break; @@ -76,7 +76,6 @@ int lan966x_xdp_run(struct lan966x_port *port, struct page *page, u32 data_len) { struct bpf_prog *xdp_prog = port->xdp_prog; struct lan966x *lan966x = port->lan966x; - struct xdp_frame *xdpf; struct xdp_buff xdp; u32 act; @@ -90,11 +89,8 @@ int lan966x_xdp_run(struct lan966x_port *port, struct page *page, u32 data_len) case XDP_PASS: return FDMA_PASS; case XDP_TX: - xdpf = xdp_convert_buff_to_frame(&xdp); - if (!xdpf) - return FDMA_DROP; - - return lan966x_fdma_xmit_xdpf(port, xdpf, page, false) ? + return lan966x_fdma_xmit_xdpf(port, page, + data_len - IFH_LEN_BYTES) ? FDMA_DROP : FDMA_TX; case XDP_REDIRECT: if (xdp_do_redirect(port->dev, &xdp, xdp_prog))
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 is possible to send it back using the page. 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, which results in higher number of transmitted frames. Bellow are the statistics: Frame size: Improvement: 64 ~8% 256 ~11% 512 ~8% 1000 ~0% 1500 ~0% Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com> --- v1->v2: - reduce number of arguments for the function lan966x_fdma_xmit_xdpf, as some of them are mutual exclusive, and other can be replaced with deduced from the other ones - update commit message and add statistics for the improvement --- .../ethernet/microchip/lan966x/lan966x_fdma.c | 43 +++++++++++-------- .../ethernet/microchip/lan966x/lan966x_main.h | 6 +-- .../ethernet/microchip/lan966x/lan966x_xdp.c | 10 ++--- 3 files changed, 31 insertions(+), 28 deletions(-)