trace_seq_used(9)

💖 trace_seq_used(9) 💖

okay bestie, you're looking at the Kernel API Manual page for trace_seq_used(9) — yes, the actual function name is right there in the title, and yes we're keeping it cute. This one is short and sweet, but the warning is lowkey important 🫶

🌸 NAME 🌸

trace_seq_used — amount of actual data written to buffer. That's the whole vibe: how much real data made it into the buffer ✨

🎀 SYNOPSIS 🎀

int trace_seq_used (struct trace_seq *s );

🦋 ARGUMENTS 🦋

• s — trace sequence descriptor. That's the little descriptor bestie you're checking on 💅

✨ DESCRIPTION ✨

Returns the amount of data written to the buffer.

IMPORTANT! 👑 Use this instead of s->seq.len if you need to pass the amount of data from the buffer to another buffer (userspace, or what not). The s->seq.len on overflow is bigger than the buffer size and using it can cause access to undefined memory. So like… do not play with that one, fr fr 😭💀

🌈 SEE ALSO 🌈

• Kernel file ./include/linux/trace_seq.h
• trace_seq_buffer_ptr(9)
• trace_seq_has_overflowed(9)
• trace_seq_pop(9)

cute little sign-off: source is ./include/linux, date is October 2026, and this page stays iconic as trace_seq_used(9) 💖✨