count_trailing_zeros(9)

💖 count_trailing_zeros(9) — a whole Kernel API Manual moment 💖

🌸 NAME 🌸

okay so bestie, count_trailing_zeros is the function that counts the number of zeros from the LSB forwards ✨

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✨ SYNOPSIS ✨

the signature is literally right here, no cap:

int count_trailing_zeros (unsigned long x );

🎀 ARGUMENTS 🎀

• x — the value 🫶

💅 DESCRIPTION 💅

okay so picture it: count_trailing_zeros counts the number of trailing zeros from the LSB going towards the MSB in x. it’s giving “how many zero bits are chilling at the end?” energy 💫

the edge cases are iconic and very much important:

• if the LSB of x is set, the result is 0.
• if only the MSB of x is set, the result is BITS_PER_LONG-1.
• if x is 0, the result is BITS_PER_LONG.

periodt, those are the numbers 💅

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🦋 SEE ALSO 🦋

also lowkey check out the kernel file ./include/linux/count_zeros.h and count_leading_zeros(9) — iykyk 👀

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🫶 this lil page comes from ./include/linux, dated October 2026, and yeah — it’s count_trailing_zeros(9). mwah, that’s the whole page bestie 💖