trace_pid_start(9)

okay so bestie, this is the Kernel API Manual, section 9, and the main character energy today belongs to trace_pid_start 💅✨ she's lowkey iconic and here to help seq_file start reading pid lists. no cap, ngl.

🌸 NAME 🌸

trace_pid_start — used for seq_file to start reading pid lists. that's the vibe check, fr fr — slay. it's giving "start the pid list" realness, literally.

✨ SYNOPSIS ✨

here's the signature, and yes you gotta keep it exactly like this, bestie:

void * trace_pid_start (struct trace_pid_list *pid_list , loff_t *pos );

🎀 ARGUMENTS 🎀

• pid_list — the pid list to show. like, the actual list on display, bestie 🫶 highkey the whole point.
• pos — the position of the file. your little bookmark in the file, iykyk.

💖 DESCRIPTION 💖

so seq_file uses this for its "start" operation — it's the thing that starts the iteration of listing pids. the way that it kicks off the whole list? obsessed, honestly. it ate. not me getting emotional over a start operation 😭

it returns pid+1 because we want to display a pid of zero, but returning NULL would stop the iteration. and we are not stopping the iteration, periodt 💀 that would be so not iconic.

🦋 SEE ALSO 🦋

the kernel file is ./kernel/trace/trace_pid.c, and the squad is:

• trace_find_filtered_pid(9)
• trace_ignore_this_task(9)
• trace_filter_add_remove_task(9)
• trace_pid_next(9)
• trace_pid_show(9)

mwah 💋 this page comes from ./kernel/trace, dated October 2026, and it's trace_pid_start(9) all day. bye bestie 🫶🌷