STRUCT PT(9)

💜 struct pt(9) — the Kernel API Manual, bestie edition ✨

okay so this is struct pt, and it's literally the per-cpu pt context. that's the whole vibe. one struct, per cpu, holding all the PT state. iconic behavior honestly 🎀

🌸 SYNOPSIS 🌸

struct pt {
    struct perf_output_handle handle;
    struct pt_filters       filters;
    int handle_nmi;
    int vmx_on;
    int pause_allowed;
    int resume_allowed;
    u64 output_base;
    u64 output_mask;
 };

no cap, that's the whole shape of it. copy it exact if you're typing it out, don't be out here freestyling the field names 💅

✨ Members ✨

here's the member-by-member breakdown, and yes i'm gonna hype each one up because they all matter:

• handle — the perf output handle. that's it, that's the field 🫶
• filters — the last configured filters. like, the filters you set most recently? those ones. kept right here ⭐
• handle_nmi — do handle PT PMI on this cpu, there's an active event. so: handle the PT PMI on this cpu, and there's an active event. that's the deal 🔥
• vmx_on — 1 if VMX is ON on this cpu. 1. VMX. ON. this cpu. simple as 🌈
• pause_allowed — PERF_EF_PAUSE is allowed to stop tracing. like, pausing is permitted here, that's what the flag is saying 🙈
• resume_allowed — PERF_EF_RESUME is allowed to start tracing. and this one's the opposite: resuming is permitted 🌸
• output_base — cached RTIT_OUTPUT_BASE MSR value. cached. MSR value. RTIT_OUTPUT_BASE. mwah 💖
• output_mask — cached RTIT_OUTPUT_MASK MSR value. same deal, but MASK instead of BASE, don't mix em up bestie 😭

ngl the two *_allowed fields are straight-up permission slips — one for stopping tracing, one for starting it back up. keep the semantics straight (PERF_EF_PAUSE = stop, PERF_EF_RESUME = start) and you're golden 👑

🦋 SEE ALSO 🦋

• the kernel file ./arch/x86/events/intel/pt.h
• struct pt_buffer(9)
• struct pt_filter(9)
• struct pt_filters(9)

go read those, they're the friend group this struct rolls with 🧚

and that's the page!! 🍓 this lil beauty comes to you from ./arch/x86/events/intel, dated October 2026, and it's struct pt(9) — the Kernel API Manual's own. mwah, go forth and read your structs 💜👑