From d65a1906b31246492449eafe9cace188cb59e26c Mon Sep 17 00:00:00 2001 From: Lorenzo Bianconi Date: Fri, 21 Jan 2022 11:09:48 +0100 Subject: net: xdp: add xdp_update_skb_shared_info utility routine Introduce xdp_update_skb_shared_info routine to update frags array metadata in skb_shared_info data structure converting to a skb from a xdp_buff or xdp_frame. According to the current skb_shared_info architecture in xdp_frame/xdp_buff and to the xdp frags support, there is no need to run skb_add_rx_frag() and reset frags array converting the buffer to a skb since the frag array will be in the same position for xdp_buff/xdp_frame and for the skb, we just need to update memory metadata. Introduce XDP_FLAGS_PF_MEMALLOC flag in xdp_buff_flags in order to mark the xdp_buff or xdp_frame as under memory-pressure if pages of the frags array are under memory pressure. Doing so we can avoid looping over all fragments in xdp_update_skb_shared_info routine. The driver is expected to set the flag constructing the xdp_buffer using xdp_buff_set_frag_pfmemalloc utility routine. Rely on xdp_update_skb_shared_info in __xdp_build_skb_from_frame routine converting the non-linear xdp_frame to a skb after performing a XDP_REDIRECT. Acked-by: Toke Hoiland-Jorgensen Acked-by: John Fastabend Acked-by: Jesper Dangaard Brouer Signed-off-by: Lorenzo Bianconi Link: https://lore.kernel.org/r/bfd23fb8a8d7438724f7819c567cdf99ffd6226f.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov --- net/core/xdp.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'net/core/xdp.c') diff --git a/net/core/xdp.c b/net/core/xdp.c index 7aba35504986..9e469f5f434c 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -561,8 +561,14 @@ struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf, struct sk_buff *skb, struct net_device *dev) { + struct skb_shared_info *sinfo = xdp_get_shared_info_from_frame(xdpf); unsigned int headroom, frame_size; void *hard_start; + u8 nr_frags; + + /* xdp frags frame */ + if (unlikely(xdp_frame_has_frags(xdpf))) + nr_frags = sinfo->nr_frags; /* Part of headroom was reserved to xdpf */ headroom = sizeof(*xdpf) + xdpf->headroom; @@ -582,6 +588,12 @@ struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf, if (xdpf->metasize) skb_metadata_set(skb, xdpf->metasize); + if (unlikely(xdp_frame_has_frags(xdpf))) + xdp_update_skb_shared_info(skb, nr_frags, + sinfo->xdp_frags_size, + nr_frags * xdpf->frame_sz, + xdp_frame_is_frag_pfmemalloc(xdpf)); + /* Essential SKB info: protocol and skb->dev */ skb->protocol = eth_type_trans(skb, dev); -- cgit v1.2.3