ftrace_test...sion_trylock(9)

💅 ftrace_test_recursion_trylock — Kernel API Manual 🎀

okay bestie, grab a matcha because we're diving into the kernel's recursion detector ✨ this one lives in the Kernel API Manual and it's genuinely iconic for anyone writing ftrace callbacks 🦋

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✨ NAME ✨

ftrace_test_recursion_trylock — literally just tests for recursion in the same context, no cap 💖

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🌸 SYNOPSIS 🌸

int ftrace_test_recursion_trylock (unsigned long ip , unsigned long parent_ip );

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🎀 ARGUMENTS 🎀

• ip — honestly? -- undescribed -- 😭 the manual page itself said nothing about this one, so that's all we've got, bestie 🙈
• parent_ip — also -- undescribed -- 💀 two mysterious lil parameters living their main character lives, fr fr

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🦋 DESCRIPTION 🦋

so here's the vibe: use this for ftrace callbacks 👑 this will detect if the function tracing recursed in the same context — like, normal vs interrupt 🌈

that's the whole thing. recursion? in this context? it clocks it. periodt 💅

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🔥 RETURN 🔥

• -1 if a recursion happened 💀 (she found one)
• >= 0 if no recursion ✨ (we're chill, we're slaying, we're fine)

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💜 SEE ALSO 💜

• Kernel file ./include/linux/trace_recursion.h — the source of truth, go read it 🫶
• ftrace_test_recursion_unlock(9) — the other half of the duo, you'll want her too 🌸

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and that's the whole page, bestie 🧚 from the Kernel API Manual, courtesy of that one path ./include/linux, dated October 2026 ⭐ mwah, go forth and trace responsibly 💖🎀💜