mmu_notifier_get_locked(9)

📦 version 7.3.1, in nixpkgs unstable

💅 mmu_notifier_get_locked(9) 💅

Okay bestie, welcome to the mmu_notifier_get_locked page from the Kernel API Manual — this one's a kernel-internals baddie and honestly it kind of ate. Let's get into it 🫶

✨ NAME ✨

mmu_notifier_get_locked — returns the single struct mmu_notifier for the mm & ops 💫

🌸 SYNOPSIS 🌸

struct mmu_notifier * mmu_notifier_get_locked (const struct
       mmu_notifier_ops *ops , struct mm_struct *mm );

Like, look at that signature. Iconic. No cap. 👑

🎀 ARGUMENTS 🎀

  • ops — the operations struct you're subscribing with. This is your vibe, your whole personality for the notifier ✨
  • mm — the mm you're attaching notifiers to. The main character of the address space, lowkey 💜

🦋 DESCRIPTION 🦋

So here's the tea, bestie: this function either allocates a brand new mmu_notifier via ops->alloc_notifier, or returns an already existing notifier that's already on the list. Two-for-one behavior, we love a flexible queen 🌈

The way it knows two notifiers are "the same"? It's literally just the value of the ops pointer. That pointer is the deciding factor — no guessing, fr fr. 👀

⚠️ Important, don't skip this part: every single call to mmu_notifier_get must be paired with a call to mmu_notifier_put. And the caller must hold the write side of mm->mmap_lock. Not optional. Not a vibe suggestion. It's giving rule of law 💀

And while the caller has a mmu_notifier get, the mm pointer will remain valid — and you can convert it into an active mm pointer via mmget_not_zero. Slay, lifetime safety 🧚

⭐ SEE ALSO ⭐

Go read them, bestie, they're all part of the same friend group 💖

Sign-off time 🌸✨

This lil masterpiece lives at ./mm, dated October 2026, and it's filed under mmu_notifier_get_locked(9). That's the whole page — go forth and get those notifiers, but like… pair them with put, okay? 😭💅

📦 where this page comes from