STRUCT LOCK_CHAIN(9)

✨ struct lock_chain(9) ✨

okay bestie, welcome to the Kernel API Manual, section 9 🎀 today's main character is struct lock_chain, which is literally the lock dependency chain record. yes, it's giving very serious kernel business. no cap.

---

🌸 NAME 🌸

struct lock_chain — the lock dependency chain record 💅

---

🦋 SYNOPSIS 🦋

ok so here's the whole vibe, exactly as it is:

struct lock_chain {
    unsigned int                    irq_context :  2, depth       :  6,
base        : 24;
    struct hlist_node               entry;
    u64 chain_key;
 };

look at her. she's got bitfields and a hash key. obsessed. 🔥

---

💖 Members 💖

one by one, bestie, we're going through the whole cast:

• irq_context — this one is exactly the same as irq_context in held_lock (you know, the one below). same energy, same meaning, no notes 💅
• depth — the number of held locks in this chain. how deep does it go? this many. periodt.
• base — the index in chain_hlocks for this chain. like, its home address in that array 🏠
• entry — the collided lock chains in the lock_chain hash list. yes, collision handling. we love a data structure that plays well with others 🫶
• chain_key — the hash key of this lock_chain. the actual key. iconic. 👑

---

🧚 SEE ALSO 🧚

go check out the kernel file ./include/linux/lockdep.h — also lockdep_set_novalidate_class(9) and lockdep_set_notrack_class(9). iykyk 💜

---

✨ a little reminder from your girl: keep every one of these fields exactly as they are, bitfield widths and all. this is kernel code, bestie, we do not freestyle here 😭

---

and that's the whole page, fr fr 🌈💖✨

kisses from the ./include/linux directory — dated October 2026 🎀 this manual page is for struct lock_chain(9) and it's a whole mood. go forth and lock safely, bestie. 🦋💅🌸