__netmem_to_nmdesc(9)

📦 version 7.3.1, in nixpkgs unstable

💅 __netmem_to_nmdesc(9)

okay so real talk, bestie — this one lives in the Kernel API Manual, and it's the unsafe speedrun version of the netmem-to-desc glow-up ✨ read the warnings, i'm literally begging 🫶

🌸 NAME

__netmem_to_nmdesc — unsafely get pointer to the &netmem_desc backing @netmem 💀

like yeah it gives you the pointer, but it does it unsafely, and the man page said what it said, so don't come crying to me 😭

✨ SYNOPSIS

struct netmem_desc * __netmem_to_nmdesc (netmem_ref netmem );

one function, one argument, no thoughts head empty, straight in and straight out 💖

🎀 ARGUMENTS

  • netmem — the netmem reference you want to convert, bestie. that's it. that's the whole input 🌸

🦋 DESCRIPTION

okay so this is the unsafe version 👀 and it can be used only when netmem is always backed by system memory. say it with me: only when it's always backed by system memory. 🔥

the tradeoff is iconic honestly — it performs faster and generates smaller object code. the way it does that? no check for the LSB, no WARN 💅 so it's just vibes and raw speed, no safety net, no little warning sign, nothing 🧚

⚠️ and here's the part where you gotta pay attention: when netmem points to IOV, this provokes undefined behaviour. not "maybe", not "kinda", provokes undefined behaviour. main character energy of the worst kind 💀🙈

🌈 RETURN

pointer to the netmem_desc — but fr fr, it's garbage if netmem is not backed by system memory 🗑️✨ it does not check. it does not warn. it just hands you a pointer and wishes you the best 🫶

👑 SEE ALSO

like the whole netmem friend group, go say hi 🦋💜

mwah 💖 that's the whole page! this lil icon ships out of ./include/net and the version vibes are stamped October 2026 — so yeah, that's the tea, go forth and please only call this when you actually know it's system memory, i believe in you 🎀⭐🍓

📦 where this page comes from