__xdp_buff_add_frag(9)

okay so you’re in the Kernel API Manual, bestie, and today’s absolute main character is __xdp_buff_add_frag(9) 💅✨

🌸 NAME 🌸

__xdp_buff_add_frag — attach frag to &xdp_buff 🎀

✨ SYNOPSIS ✨

bool __xdp_buff_add_frag (struct xdp_buff *xdp , netmem_ref netmem , u32 offset , u32 size , u32 truesize , bool try_coalesce );

🎀 ARGUMENTS 🎀

• xdp — the XDP buffer to attach the frag to 🫶
• netmem — network memory containing the frag
• offset — offset at which the frag starts
• size — size of the frag
• truesize — total memory size occupied by the frag
• try_coalesce — whether to try coalescing the frags (not valid for XSk) 🚫

💖 DESCRIPTION 💖

okay so here’s the tea: attach the frag to the XDP buffer. If it currently has no frags attached, initialize the related fields; otherwise check that the frag number didn’t reach the limit of MAX_SKB_FRAGS. If possible, try coalescing the frag with the previous one. 🔥

The function doesn’t check/update the pfmemalloc bit. Please use the non-underscored wrapper in drivers. 🙈

bestie, for real, please use the non-underscored wrapper in drivers 💖

🔥 RETURN 🔥

true on success, false if there’s no space for the frag in the shared info struct. periodt. 💀

🦋 SEE ALSO 🦋

• Kernel file ./include/net/xdp.h
• XDP RX-queue information(9)
• xdp_buff_add_frag(9)
• xdp_rxq_info_attach_mem_model(9)
• xdp_rxq_info_detach_mem_model(9)

xoxo, your girl from ./include/net — October 2026 — signing off for __xdp_buff_add_frag(9) 💋🎀