rcu_read_unlock_trace(9)

💅 rcu_read_unlock_trace(9)

okay so bestie, this is a page from the Kernel API Manual (the 9 section, kernel devs only, iykyk) and it's about one tiny little function that closes out an RCU-trace read-side critical section. short page. important job. let's get into it 🎀

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✨ NAME ✨

rcu_read_unlock_trace — the "and that's a wrap" for an RCU-trace read-side critical section 🦋

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🌸 SYNOPSIS 🌸

void rcu_read_unlock_trace (void );

that's it. that's the whole call. no args, no drama, no nothing 💅

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🎀 ARGUMENTS 🎀

• void — no arguments. zero. none. void girl summer 🫶

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💖 DESCRIPTION 💖

so here's the vibe: this function is the literal other half of a rcu_read_lock_trace call. you lock, you do your thing, you call this, and the section is done. pairs with a preceding call to rcu_read_lock_trace, no cap ✨

nesting? allowed. go off, stack them if you need to, she doesn't mind 🌸

⚠️ but bestie. listen. invoking rcu_read_unlock_trace when there is no matching rcu_read_lock_trace is verboten — literally forbidden, not cute at all — and it will result in lockdep complaints 😭 lockdep will absolutely call you out in the group chat.

want the full lore? for more details, please see the documentation for rcu_read_unlock. same energy, different lock family 🧚

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🔥 SEE ALSO 🔥

• Kernel file ./include/linux/rcupdate_trace.h — the source of truth, go read her 👑
• rcu_read_lock_tasks_trace(9)
• rcu_read_unlock_tasks_trace(9)
• rcu_read_lock_trace(9)
• call_rcu_tasks_trace(9)
• synchronize_rcu_tasks_trace(9)
• rcu_barrier_tasks_trace(9)
• rcu_tasks_trace_expedite_current(9)

like, the whole tasks-trace friend group. follow them all, they're all iconic ⭐

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vibe check recap: one call, no args, must match a rcu_read_lock_trace, nesting is fine, and an unmatched unlock gets you a lockdep complaint fr fr. that's the whole tea 💀

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later babes 💜 this one lives under ./include/linux, dated October 2026, and it's rcu_read_unlock_trace(9) — don't forget her name 🍓