synth_event_add_next_val(9)

📦 version 7.3.1, in nixpkgs unstable

✨ synth_event_add_next_val(9) ✨

okay so bestie, this one lives in the Kernel API Manual and it's literally the glow-up your synthetic trace events have been waiting for 🦋

🎀 NAME 🎀

synth_event_add_next_val — add the next field's value to an open synth trace 💅

🌸 SYNOPSIS 🌸

int synth_event_add_next_val (u64 val , struct synth_event_trace_state *trace_state );

✨ ARGUMENTS ✨

  • val — the value you're setting the next field to 🫶
  • trace_state — a pointer to the object that's tracking your piecewise trace state, iykyk

💖 DESCRIPTION 💖

So what this does is set the value of the next field in an event that's already been opened up by synth_event_trace_start. That's the whole vibe 💫

The val param should be the value cast to u64. And if the value is actually pointing at a string? Then val should be a char * cast to u64. No cap, that's just how it goes.

This function assumes all the fields in an event are getting set one after another — like, you make successive calls to this function, one for each field, in the order of the fields in the event, until every single field has been set. Main character energy: strict order, no skipping 🎯

But if you'd rather set each field individually without caring about ordering at all? Then synth_event_add_val can be used instead. Pick your fighter 💅

⚠️ Note however that synth_event_add_next_val and synth_event_add_val can't be intermixed for a given event trace — it's one or the other, but not both at the same time. fr fr, don't try it.
🚨 Note also that synth_event_trace_end must be called after all values have been added for each event trace — regardless of whether adding all the field values succeeded or not. Like, even if it flopped, you still call it. periodt.

🔥 RETURN 🔥

0 on success, err otherwise. slay 🎀

🌈 SEE ALSO 🌈

Kernel file ./kernel/trace/trace_events_synth.c 👑

okay that's the whole page, bestie 💜 this one's from the ./kernel/trace corner of the world, dated October 2026, and it's literally synth_event_add_next_val(9) — go forth and add those values in order, you icon 👑🌸

📦 where this page comes from