Re: [PATCH bpf-next v1 1/2] xdp: recycle Page Pool backed skbs built from XDP frames

From: kernel test robot
Date: Wed Mar 01 2023 - 14:09:23 EST


Hi Alexander,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on bpf-next/master]

url: https://github.com/intel-lab-lkp/linux/commits/Alexander-Lobakin/xdp-recycle-Page-Pool-backed-skbs-built-from-XDP-frames/20230302-000635
base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
patch link: https://lore.kernel.org/r/20230301160315.1022488-2-aleksander.lobakin%40intel.com
patch subject: [PATCH bpf-next v1 1/2] xdp: recycle Page Pool backed skbs built from XDP frames
config: i386-randconfig-a001 (https://download.01.org/0day-ci/archive/20230302/202303020331.PSFMFbXw-lkp@xxxxxxxxx/config)
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce (this is a W=1 build):
# https://github.com/intel-lab-lkp/linux/commit/a5ca5578e9bd35220be091fd02df96d492120ee3
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Alexander-Lobakin/xdp-recycle-Page-Pool-backed-skbs-built-from-XDP-frames/20230302-000635
git checkout a5ca5578e9bd35220be091fd02df96d492120ee3
# save the config file
mkdir build_dir && cp config build_dir/.config
make W=1 O=build_dir ARCH=i386 olddefconfig
make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Link: https://lore.kernel.org/oe-kbuild-all/202303020331.PSFMFbXw-lkp@xxxxxxxxx/

All errors (new ones prefixed by >>):

net/core/xdp.c: In function '__xdp_build_skb_from_frame':
>> net/core/xdp.c:662:17: error: implicit declaration of function 'skb_mark_for_recycle' [-Werror=implicit-function-declaration]
662 | skb_mark_for_recycle(skb);
| ^~~~~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors


vim +/skb_mark_for_recycle +662 net/core/xdp.c

614
615 struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf,
616 struct sk_buff *skb,
617 struct net_device *dev)
618 {
619 struct skb_shared_info *sinfo = xdp_get_shared_info_from_frame(xdpf);
620 unsigned int headroom, frame_size;
621 void *hard_start;
622 u8 nr_frags;
623
624 /* xdp frags frame */
625 if (unlikely(xdp_frame_has_frags(xdpf)))
626 nr_frags = sinfo->nr_frags;
627
628 /* Part of headroom was reserved to xdpf */
629 headroom = sizeof(*xdpf) + xdpf->headroom;
630
631 /* Memory size backing xdp_frame data already have reserved
632 * room for build_skb to place skb_shared_info in tailroom.
633 */
634 frame_size = xdpf->frame_sz;
635
636 hard_start = xdpf->data - headroom;
637 skb = build_skb_around(skb, hard_start, frame_size);
638 if (unlikely(!skb))
639 return NULL;
640
641 skb_reserve(skb, headroom);
642 __skb_put(skb, xdpf->len);
643 if (xdpf->metasize)
644 skb_metadata_set(skb, xdpf->metasize);
645
646 if (unlikely(xdp_frame_has_frags(xdpf)))
647 xdp_update_skb_shared_info(skb, nr_frags,
648 sinfo->xdp_frags_size,
649 nr_frags * xdpf->frame_sz,
650 xdp_frame_is_frag_pfmemalloc(xdpf));
651
652 /* Essential SKB info: protocol and skb->dev */
653 skb->protocol = eth_type_trans(skb, dev);
654
655 /* Optional SKB info, currently missing:
656 * - HW checksum info (skb->ip_summed)
657 * - HW RX hash (skb_set_hash)
658 * - RX ring dev queue index (skb_record_rx_queue)
659 */
660
661 if (xdpf->mem.type == MEM_TYPE_PAGE_POOL)
> 662 skb_mark_for_recycle(skb);
663
664 /* Allow SKB to reuse area used by xdp_frame */
665 xdp_scrub_frame(xdpf);
666
667 return skb;
668 }
669 EXPORT_SYMBOL_GPL(__xdp_build_skb_from_frame);
670

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https://github.com/intel/lkp-tests