Re: [PATCH v12 bpf-next 01/18] net: skbuff: add size metadata to skb_shared_info for xdp

Lorenzo Bianconi wrote:

quoted

Introduce xdp_frags_tsize field in skb_shared_info data structure
to store xdp_buff/xdp_frame truesize (xdp_frags_tsize will be used
in xdp multi-buff support). In order to not increase skb_shared_info
size we will use a hole due to skb_shared_info alignment.
Introduce xdp_frags_size field in skb_shared_info data structure
reusing gso_type field in order to store xdp_buff/xdp_frame paged size.
xdp_frags_size will be used in xdp multi-buff support.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>

I assume we can use xdp_frags_tsize for anything else above XDP later?
Other than simple question looks OK to me.

yes, right as we did for gso_type/xdp_frags_size.

Regards,
Lorenzo

Acked-by: John Fastabend <john.fastabend@gmail.com>

quoted

---
 include/linux/skbuff.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 6bdb0db3e825..1abeba7ef82e 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h

@@ -522,13 +522,17 @@ struct skb_shared_info {
      unsigned short  gso_segs;
      struct sk_buff  *frag_list;
      struct skb_shared_hwtstamps hwtstamps;
-     unsigned int    gso_type;
+     union {
+             unsigned int    gso_type;
+             unsigned int    xdp_frags_size;
+     };
      u32             tskey;

      /*
       * Warning : all fields before dataref are cleared in __alloc_skb()
       */
      atomic_t        dataref;
+     unsigned int    xdp_frags_tsize;

      /* Intermediate layers must ensure that destructor_arg
       * remains valid until skb destructor */
--

2.31.1