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System

Lightweight Profiling instructions (AMD)

Lightweight Profiling (LWP) lets a program count and sample its own events into a ring buffer in memory, without entering the kernel.

An AMD extension: Intel processors do not have this instruction.

CPUID
LWP
CPUID.80000001H:ECX[15]
Instructions
4 mnemonics
Processors
Bulldozer, Piledriver

Instructions

Mnemonics with at least one form in LWP. Each page lists all forms of the mnemonic, including those of other extensions.
MnemonicSummaryForms
LLWPCBLoads the address of a Lightweight Profiling control block from a register and starts profiling with it; LWP.1
LWPINSInserts a record with a value of the program's choosing into the Lightweight Profiling ring buffer; LWP.2
LWPVALCounts a programmed value sample event of Lightweight Profiling and records it when its counter runs out; LWP.2
SLWPCBStores the Lightweight Profiling state to memory and returns the address of its control block in a register; LWP.1

CPUID and processors

XED splits LWP into 1 ISA set. Software can use a form when the processor reports every CPUID bit of one alternative of the form's ISA set.

XED ISA sets of LWP. Alternatives are separated by “or”; processors follow XED’s chip model, whose AMD processors end with Zen 2, and the CPU data of this site for Zen 3 to Zen 6.
ISA setCPUIDProcessors
LWP

LWP
CPUID.80000001H:ECX[15] LWP

Bulldozer, Piledriver

Sources

  1. Intel XED v2026.08.23 (commit 0bcb6237345c): forms, encodings, ISA sets, CPUID bits and chip model.
  2. AMD64 Architecture Programmer's Manual, Volume 3: General-Purpose and System Instructions (24594, rev. 3.38, July 2026)
  3. AMD64 Architecture Programmer's Manual, Volume 2: System Programming (24593, rev. 3.45, July 2026)

The tables are derived from Intel XED, Copyright Intel Corporation, licensed under the Apache License 2.0; x86-64.net converted and reformatted them. The text is our own.