| Message ID | 20250325044358.2675384-1-skhawaja@google.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next] xsk: Bring back busy polling support in XDP_COPY | expand |
On Mon, Mar 24, 2025 at 9:43 PM Samiullah Khawaja <skhawaja@google.com> wrote: > > Commit 5ef44b3cb43b ("xsk: Bring back busy polling support") fixed the > busy polling support in xsk for XDP_ZEROCOPY after it was broken in > commit 86e25f40aa1e ("net: napi: Add napi_config"). The busy polling > support with XDP_COPY remained broken since the napi_id setup in > xsk_rcv_check was removed. > > Bring back the setup of napi_id for XDP_COPY so socket level SO_BUSYPOLL > can be used to poll the underlying napi. > > Tested using AF_XDP support in virtio-net by running the xsk_rr AF_XDP > benchmarking tool shared here: > https://lore.kernel.org/all/20250320163523.3501305-1-skhawaja@google.com/T/ > > Enabled socket busy polling using following commands in qemu, > > ``` > sudo ethtool -L eth0 combined 1 > sudo ethtool -G eth0 rx 1024 > echo 400 | sudo tee /proc/sys/net/core/busy_read > echo 100 | sudo tee /sys/class/net/eth0/napi_defer_hard_irqs > echo 15000 | sudo tee /sys/class/net/eth0/gro_flush_timeout > ``` > > Fixes: 5ef44b3cb43b ("xsk: Bring back busy polling support") > Fixes: 86e25f40aa1e ("net: napi: Add napi_config") > Signed-off-by: Samiullah Khawaja <skhawaja@google.com> > --- > net/xdp/xsk.c | 22 +++++++++++++++------- > 1 file changed, 15 insertions(+), 7 deletions(-) > > diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c > index e5d104ce7b82..de8bf97b2cb9 100644 > --- a/net/xdp/xsk.c > +++ b/net/xdp/xsk.c > @@ -310,6 +310,18 @@ static bool xsk_is_bound(struct xdp_sock *xs) > return false; > } > > +static void __xsk_mark_napi_id_once(struct sock *sk, struct net_device *dev, u32 qid) > +{ > + struct netdev_rx_queue *rxq; > + > + if (qid >= dev->real_num_rx_queues) > + return; > + > + rxq = __netif_get_rx_queue(dev, qid); > + if (rxq->napi) > + __sk_mark_napi_id_once(sk, rxq->napi->napi_id); > +} > + > static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) > { > if (!xsk_is_bound(xs)) > @@ -323,6 +335,7 @@ static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) > return -ENOSPC; > } > > + __xsk_mark_napi_id_once(&xs->sk, xs->dev, xs->queue_id); > return 0; > } > > @@ -1300,13 +1313,8 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) > xs->queue_id = qid; > xp_add_xsk(xs->pool, xs); > > - if (xs->zc && qid < dev->real_num_rx_queues) { > - struct netdev_rx_queue *rxq; > - > - rxq = __netif_get_rx_queue(dev, qid); > - if (rxq->napi) > - __sk_mark_napi_id_once(sk, rxq->napi->napi_id); > - } > + if (xs->zc) > + __xsk_mark_napi_id_once(sk, dev, qid); > > out_unlock: > if (err) { > -- > 2.49.0.395.g12beb8f557-goog > The original commit 5ef44b3cb43b ("xsk: Bring back busy polling support") has landed in 6.13 so I will revise this and resend it to the net. Thanks
On 03/25, Samiullah Khawaja wrote: > Commit 5ef44b3cb43b ("xsk: Bring back busy polling support") fixed the > busy polling support in xsk for XDP_ZEROCOPY after it was broken in > commit 86e25f40aa1e ("net: napi: Add napi_config"). The busy polling > support with XDP_COPY remained broken since the napi_id setup in > xsk_rcv_check was removed. > > Bring back the setup of napi_id for XDP_COPY so socket level SO_BUSYPOLL > can be used to poll the underlying napi. > > Tested using AF_XDP support in virtio-net by running the xsk_rr AF_XDP > benchmarking tool shared here: > https://lore.kernel.org/all/20250320163523.3501305-1-skhawaja@google.com/T/ > > Enabled socket busy polling using following commands in qemu, > > ``` > sudo ethtool -L eth0 combined 1 > sudo ethtool -G eth0 rx 1024 > echo 400 | sudo tee /proc/sys/net/core/busy_read > echo 100 | sudo tee /sys/class/net/eth0/napi_defer_hard_irqs > echo 15000 | sudo tee /sys/class/net/eth0/gro_flush_timeout > ``` > > Fixes: 5ef44b3cb43b ("xsk: Bring back busy polling support") > Fixes: 86e25f40aa1e ("net: napi: Add napi_config") > Signed-off-by: Samiullah Khawaja <skhawaja@google.com> > --- > net/xdp/xsk.c | 22 +++++++++++++++------- > 1 file changed, 15 insertions(+), 7 deletions(-) > > diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c > index e5d104ce7b82..de8bf97b2cb9 100644 > --- a/net/xdp/xsk.c > +++ b/net/xdp/xsk.c > @@ -310,6 +310,18 @@ static bool xsk_is_bound(struct xdp_sock *xs) > return false; > } > > +static void __xsk_mark_napi_id_once(struct sock *sk, struct net_device *dev, u32 qid) > +{ > + struct netdev_rx_queue *rxq; > + > + if (qid >= dev->real_num_rx_queues) > + return; > + > + rxq = __netif_get_rx_queue(dev, qid); > + if (rxq->napi) > + __sk_mark_napi_id_once(sk, rxq->napi->napi_id); > +} > + > static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) > { > if (!xsk_is_bound(xs)) > @@ -323,6 +335,7 @@ static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) > return -ENOSPC; > } [..] > + __xsk_mark_napi_id_once(&xs->sk, xs->dev, xs->queue_id); > return 0; > } Can we move this part to a different place? __xsk_rcv maybe? So it doesn't trigger for the zc case where napi is resolved at bind time.
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index e5d104ce7b82..de8bf97b2cb9 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -310,6 +310,18 @@ static bool xsk_is_bound(struct xdp_sock *xs) return false; } +static void __xsk_mark_napi_id_once(struct sock *sk, struct net_device *dev, u32 qid) +{ + struct netdev_rx_queue *rxq; + + if (qid >= dev->real_num_rx_queues) + return; + + rxq = __netif_get_rx_queue(dev, qid); + if (rxq->napi) + __sk_mark_napi_id_once(sk, rxq->napi->napi_id); +} + static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) { if (!xsk_is_bound(xs)) @@ -323,6 +335,7 @@ static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) return -ENOSPC; } + __xsk_mark_napi_id_once(&xs->sk, xs->dev, xs->queue_id); return 0; } @@ -1300,13 +1313,8 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) xs->queue_id = qid; xp_add_xsk(xs->pool, xs); - if (xs->zc && qid < dev->real_num_rx_queues) { - struct netdev_rx_queue *rxq; - - rxq = __netif_get_rx_queue(dev, qid); - if (rxq->napi) - __sk_mark_napi_id_once(sk, rxq->napi->napi_id); - } + if (xs->zc) + __xsk_mark_napi_id_once(sk, dev, qid); out_unlock: if (err) {
Commit 5ef44b3cb43b ("xsk: Bring back busy polling support") fixed the busy polling support in xsk for XDP_ZEROCOPY after it was broken in commit 86e25f40aa1e ("net: napi: Add napi_config"). The busy polling support with XDP_COPY remained broken since the napi_id setup in xsk_rcv_check was removed. Bring back the setup of napi_id for XDP_COPY so socket level SO_BUSYPOLL can be used to poll the underlying napi. Tested using AF_XDP support in virtio-net by running the xsk_rr AF_XDP benchmarking tool shared here: https://lore.kernel.org/all/20250320163523.3501305-1-skhawaja@google.com/T/ Enabled socket busy polling using following commands in qemu, ``` sudo ethtool -L eth0 combined 1 sudo ethtool -G eth0 rx 1024 echo 400 | sudo tee /proc/sys/net/core/busy_read echo 100 | sudo tee /sys/class/net/eth0/napi_defer_hard_irqs echo 15000 | sudo tee /sys/class/net/eth0/gro_flush_timeout ``` Fixes: 5ef44b3cb43b ("xsk: Bring back busy polling support") Fixes: 86e25f40aa1e ("net: napi: Add napi_config") Signed-off-by: Samiullah Khawaja <skhawaja@google.com> --- net/xdp/xsk.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-)