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| author | Stanislav Fomichev <sdf@fomichev.me> | 2025-01-08 16:34:36 -0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-01-10 18:07:56 -0800 |
| commit | 5ef44b3cb43bda4009ba7fe3d54e0d258ae4aee7 (patch) | |
| tree | 89dd1c25f659def19c1d49b77f49416138434e02 /net/xdp | |
| parent | f0aa6a37a3dbb40b272df5fc6db93c114688adcd (diff) | |
| download | linux-5ef44b3cb43bda4009ba7fe3d54e0d258ae4aee7.tar.gz linux-5ef44b3cb43bda4009ba7fe3d54e0d258ae4aee7.tar.bz2 linux-5ef44b3cb43bda4009ba7fe3d54e0d258ae4aee7.zip | |
xsk: Bring back busy polling support
Commit 86e25f40aa1e ("net: napi: Add napi_config") moved napi->napi_id
assignment to a later point in time (napi_hash_add_with_id). This breaks
__xdp_rxq_info_reg which copies napi_id at an earlier time and now
stores 0 napi_id. It also makes sk_mark_napi_id_once_xdp and
__sk_mark_napi_id_once useless because they now work against 0 napi_id.
Since sk_busy_loop requires valid napi_id to busy-poll on, there is no way
to busy-poll AF_XDP sockets anymore.
Bring back the ability to busy-poll on XSK by resolving socket's napi_id
at bind time. This relies on relatively recent netif_queue_set_napi,
but (assume) at this point most popular drivers should have been converted.
This also removes per-tx/rx cycles which used to check and/or set
the napi_id value.
Confirmed by running a busy-polling AF_XDP socket
(github.com/fomichev/xskrtt) on mlx5 and looking at BusyPollRxPackets
from /proc/net/netstat.
Fixes: 86e25f40aa1e ("net: napi: Add napi_config")
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20250109003436.2829560-1-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/xdp')
| -rw-r--r-- | net/xdp/xsk.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 3fa70286c846..89d2bef96469 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -322,7 +322,6 @@ static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) return -ENOSPC; } - sk_mark_napi_id_once_xdp(&xs->sk, xdp); return 0; } @@ -908,11 +907,8 @@ static int __xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len if (unlikely(!xs->tx)) return -ENOBUFS; - if (sk_can_busy_loop(sk)) { - if (xs->zc) - __sk_mark_napi_id_once(sk, xsk_pool_get_napi_id(xs->pool)); + if (sk_can_busy_loop(sk)) sk_busy_loop(sk, 1); /* only support non-blocking sockets */ - } if (xs->zc && xsk_no_wakeup(sk)) return 0; @@ -1298,6 +1294,14 @@ 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); + } + out_unlock: if (err) { dev_put(dev); |