pr_debug(9)

💜 pr_debug(9) — a Kernel API Manual moment 💜

okay so bestie, welcome to the Kernel API Manual ✨ this one's short and sweet and honestly kind of an underrated icon in the printk friend group 🫶

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🎀 NAME 🎀

pr_debug — prints a debug-level message, but conditionally 👀 like it's very "i'll show up if the vibes are right" energy

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✨ SYNOPSIS ✨

pr_debug (fmt , ... );

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🌸 ARGUMENTS 🌸

• fmt — the format string, aka the blueprint of your message 💅
• ... — the arguments for that format string, the lil fill-in-the-blanks 🧚

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🦋 DESCRIPTION 🦋

okay so here's the tea ☕ this macro is a little shapeshifter and its whole personality depends on your config, no cap:

• if CONFIG_DYNAMIC_DEBUG is set, it expands to dynamic_pr_debug 🔥
• otherwise, if DEBUG is defined, it's literally equivalent to a printk with KERN_DEBUG loglevel, iconic behavior 💀
• and if DEBUG is not defined? it does nothing. absolutely nothing. ghost mode 👻 honestly respect

it uses pr_fmt to generate the format string — and yeah, dynamic_pr_debug uses pr_fmt internally too, so the whole fam is on the same page there 🌈

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👑 SEE ALSO 👑

Kernel file ./include/linux/printk.h — the mothership 🚀 and the whole squad:

• printk_cpu_sync_get_irqsave(9)
• printk_cpu_sync_put_irqrestore(9)
• pr_fmt(9)
• printk(9)
• pr_emerg(9)
• pr_alert(9)
• pr_crit(9)
• pr_err(9)
• pr_warn(9)
• pr_notice(9)
• pr_info(9)
• pr_cont(9)
• pr_devel(9)
• print_hex_dump_bytes(9)

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💖 and that's the whole page bestie, short king energy fr fr 🍓

okay so this came at you straight from ./include/linux, dated October 2026, and it's pr_debug(9) signing off — mwah 💋 go log something cute 🦋✨