tcf_em_register(9)

💖 tcf_em_register(9) — like, the extended-match registration era 💖

okay so this is a page from the Kernel API Manual, bestie, and it's about tcf_em_register — yes it's a mouthful, no we're not renaming it, it's iconic as is 💅

---

✨ NAME ✨

tcf_em_register — register an extended match 🎀

---

🌸 SYNOPSIS 🌸

int tcf_em_register (struct tcf_ematch_ops *ops );

---

🦋 ARGUMENTS 🦋

• ops — the ematch operations lookup table. that's the whole vibe, it's what you're handing over 🫶

---

⭐ DESCRIPTION ⭐

so here's the tea ☕ — this function is the one ematches must call to, like, announce their presence to the world. main character announcement energy, no cap 👑

a couple of non-negotiables before you go calling it, though:

• the ops you pass in must have kind set to a unique identifier 🔑
• the callback match must be implemented — that one's not optional, periodt

literally everything else? optional, bestie. all the other callbacks can be left out and a fallback implementation gets used instead 🌈 lowkey generous of the kernel tbh

and if you try to register an ematch whose kind is already taken? you get -EEXISTS back 😭 like the kernel's politely telling you that kind is so already registered.

---

💜 SEE ALSO 💜

Kernel file ./net/sched/ematch.c — go read it, it's giving source-of-truth 💫

• tcf_em_unregister(9)
• tcf_em_tree_validate(9)
• tcf_em_tree_destroy(9)
• tcf_em_tree_dump(9)

---

okay that's the whole page, you ate it up fr fr 🍓 this little love letter lives in ./net/sched, dated October 2026, and that's the sign-off bestie — bye, slay, go register some matches 💖✨🧚