[bpf-next V1 PATCH 8/8] bpf/xdp: devmap can avoid calling ndo_xdp_flush
From: Jesper Dangaard Brouer <hidden>
Date: 2018-05-30 18:01:15
Subsystem:
bpf [general] (safe dynamic programs and tools), the rest, xdp (express data path) · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds, David S. Miller, Jakub Kicinski, Jesper Dangaard Brouer, John Fastabend
The XDP_REDIRECT map devmap can avoid using ndo_xdp_flush, by instead instructing ndo_xdp_xmit to flush via XDP_XMIT_FLUSH flag in appropriate places. Notice after this patch it is possible to remove ndo_xdp_flush completely, as this is the last user of ndo_xdp_flush. This is left for later patches, to keep driver changes separate. Signed-off-by: Jesper Dangaard Brouer <redacted> --- kernel/bpf/devmap.c | 20 +++++++------------- 1 file changed, 7 insertions(+), 13 deletions(-)
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index 04fbd75a5274..9c846a7a8cff 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c@@ -217,7 +217,7 @@ void __dev_map_insert_ctx(struct bpf_map *map, u32 bit) } static int bq_xmit_all(struct bpf_dtab_netdev *obj, - struct xdp_bulk_queue *bq) + struct xdp_bulk_queue *bq, bool flush) { struct net_device *dev = obj->dev; int sent = 0, drops = 0, err = 0;
@@ -232,7 +232,8 @@ static int bq_xmit_all(struct bpf_dtab_netdev *obj, prefetch(xdpf); } - sent = dev->netdev_ops->ndo_xdp_xmit(dev, bq->count, bq->q, 0); + sent = dev->netdev_ops->ndo_xdp_xmit(dev, bq->count, bq->q, + flush ? XDP_XMIT_FLUSH : 0); if (sent < 0) { err = sent; sent = 0;
@@ -276,7 +277,6 @@ void __dev_map_flush(struct bpf_map *map) for_each_set_bit(bit, bitmap, map->max_entries) { struct bpf_dtab_netdev *dev = READ_ONCE(dtab->netdev_map[bit]); struct xdp_bulk_queue *bq; - struct net_device *netdev; /* This is possible if the dev entry is removed by user space * between xdp redirect and flush op.
@@ -287,10 +287,7 @@ void __dev_map_flush(struct bpf_map *map) __clear_bit(bit, bitmap); bq = this_cpu_ptr(dev->bulkq); - bq_xmit_all(dev, bq); - netdev = dev->dev; - if (likely(netdev->netdev_ops->ndo_xdp_flush)) - netdev->netdev_ops->ndo_xdp_flush(netdev); + bq_xmit_all(dev, bq, true); } }
@@ -320,7 +317,7 @@ static int bq_enqueue(struct bpf_dtab_netdev *obj, struct xdp_frame *xdpf, struct xdp_bulk_queue *bq = this_cpu_ptr(obj->bulkq); if (unlikely(bq->count == DEV_MAP_BULK_SIZE)) - bq_xmit_all(obj, bq); + bq_xmit_all(obj, bq, false); /* Ingress dev_rx will be the same for all xdp_frame's in * bulk_queue, because bq stored per-CPU and must be flushed
@@ -359,8 +356,7 @@ static void *dev_map_lookup_elem(struct bpf_map *map, void *key) static void dev_map_flush_old(struct bpf_dtab_netdev *dev) { - if (dev->dev->netdev_ops->ndo_xdp_flush) { - struct net_device *fl = dev->dev; + if (dev->dev->netdev_ops->ndo_xdp_xmit) { struct xdp_bulk_queue *bq; unsigned long *bitmap;
@@ -371,9 +367,7 @@ static void dev_map_flush_old(struct bpf_dtab_netdev *dev) __clear_bit(dev->bit, bitmap); bq = per_cpu_ptr(dev->bulkq, cpu); - bq_xmit_all(dev, bq); - - fl->netdev_ops->ndo_xdp_flush(dev->dev); + bq_xmit_all(dev, bq, true); } } }