STRUCT DELAYED_FREE(9)

✨ struct delayed_free(9) ✨

okay bestie, so this is a kernel API page — the <cyan>struct delayed_free</cyan> one — and honestly it's giving "small struct, big responsibilities" energy. let's get into it 💅

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🌸 NAME 🌸

struct delayed_free — the data structures used for delayed freeing. that's it, that's the vibe 🎀

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✨ SYNOPSIS ✨

like, here's the whole thing, verbatim, no cap:

struct delayed_free {
    struct rcu_head         rcu_head;
    int index;
    int scheduled;
    struct pending_free     pf[2];
 };

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🦋 Members 🦋

• rcu_head — this one's used to schedule an RCU callback for freeing data structures. it's the little hook that makes the whole "delayed" thing happen ⭐
• index — the index of pf that freed data structures get added to. yes, pf is plural-ish and this is your pointer into it 👑
• scheduled — literally just tracks whether or not an RCU callback has been scheduled. a yes/no situation, we love a boolean-ish girlie 🫶
• pf — an array holding information about the data structures that are about to be freed. it's the receipts pile 🙈

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💖 Description 💖

so picture this: it's a data structure for delayed freeing of data structures that might still be getting accessed by RCU readers at the exact moment those things were freed. which is a whole mess if you don't delay — so we delay. iconic behaviour, honestly 🔥

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🌈 SEE ALSO 🌈

• Kernel file ./kernel/locking/lockdep.c
• struct pending_free(9)
• struct lock_trace(9)
• lockdep_hardirqs_on_prepare(9)
• lockdep_cleanup_dead_cpu(9)

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that's the whole page bestie, you ate that. this one lives in ./kernel/locking, it's dated October 2026, and it's from the Kernel API Manual — mwah, go forth and delay your frees responsibly 💜🧚