pt_buffer_setup_aux(9)

💅 pt_buffer_setup_aux(9) 💅

okay so bestie, welcome to the Kernel API Manual — we're literally about to set up ToPA tables together and it's gonna slay ✨

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🌸 NAME 🌸

pt_buffer_setup_aux — set up topa tables for a PT buffer 🎀

🦋 SYNOPSIS 🦋

void * pt_buffer_setup_aux (struct perf_event *event , void **pages ,
       int nr_pages , bool snapshot );

✨ ARGUMENTS ✨

• event — the performance event, your main character 🫶
• pages — array of pointers to buffer pages, handed down from perf core
• nr_pages — how many pages are in the buffer, no cap
• snapshot — if this is a snapshot/overwrite counter 👀

💖 DESCRIPTION 💖

so this is a pmu::setup_aux callback, and what it does is set up the ToPA tables and all the bookkeeping for an AUX buffer. like, the whole entire vibe. tables? handled. bookkeeping? handled. iconic behaviour only 💅

🔥 RETURN 🔥

our private PT buffer structure 💀 (it's ours, we made it, we're obsessed)

🌈 SEE ALSO 🌈

honestly the whole friend group showed up for this one:

• struct topa(9)
• struct topa_page(9)
• topa_alloc(9)
• topa_free(9)
• topa_insert_table(9)
• topa_table_full(9)
• topa_insert_pages(9)
• pt_topa_dump(9)
• pt_buffer_advance(9)
• pt_update_head(9)
• pt_buffer_region(9)
• pt_buffer_region_size(9)
• pt_handle_status(9)
• pt_read_offset(9)
• pt_buffer_reset_markers(9)
• pt_buffer_reset_offsets(9)
• pt_buffer_fini_topa(9)
• pt_buffer_init_topa(9)
• pt_buffer_free_aux(9)
• intel_pt_interrupt(9)

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bestie this one lives in the kernel file ./arch/x86/events/intel/pt.c — go read it iykyk 📖

and that's the whole page!! mwah 💋 this came out of ./arch/x86/events/intel, dated October 2026, and it's genuinely giving reference documentation. periodt. 👑🧚💜