linux-kernel/xxxx-clang-ml-inliner.patch at main · mauri870/linux-kernel · GitHub

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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Mauri de Souza Meneguzzo <mauri870@gmail.com>
Date: Thu, 10 Apr 2026 00:00:00 +0000
Subject: [PATCH] kbuild: Add support for Clang ML-guided inliner and register
 allocator

Enable LLVM's machine-learning-based inliner and register allocation
advisor when building with Clang. These models use offline-trained ML
models to make better inlining and register allocation decisions than
the heuristic-based defaults.

The flags require a Clang/LLVM toolchain compiled with ML support
(i.e. LLVM built with the MLGO release models embedded). Use
-enable-ml-inliner=release and -regalloc-enable-advisor=release to
activate the release-mode models.

Signed-off-by: Mauri de Souza Meneguzzo <mauri870@gmail.com>
---
 Makefile     |  5 +++++
 init/Kconfig | 13 +++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/Makefile b/Makefile
index e8737f5ea..000000001 100644
--- a/Makefile
+++ b/Makefile
@@ -886,5 +886,10 @@ ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
 KBUILD_CFLAGS	+= -mllvm -polly-run-dce
 endif
 endif

+ifdef CONFIG_CLANG_ML_INLINER
+KBUILD_CFLAGS	+= -mllvm -enable-ml-inliner=release \
+		   -mllvm -regalloc-enable-advisor=release
+endif
+
 # Tell gcc to never replace conditional load with a non-conditional one
diff --git a/init/Kconfig b/init/Kconfig
index 66adb2fc9..000000002 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -263,6 +263,19 @@ config POLLY_CLANG

 	    https://polly.llvm.org

+config CLANG_ML_INLINER
+	bool "Use Clang ML-guided inliner and register allocator"
+	depends on CC_IS_CLANG && $(cc-option,-mllvm -enable-ml-inliner=release)
+	depends on !COMPILE_TEST
+	help
+	  This option enables Clang's machine-learning-guided inliner and
+	  register allocation advisor. Both use offline-trained MLGO models
+	  to make better decisions than the default heuristics, at no extra
+	  runtime cost. This requires a Clang toolchain compiled with the
+	  MLGO release models embedded (LLVM built with
+	  LLVM_INLINER_MODEL_PATH and LLVM_REGALLOC_MODEL_PATH pointing to
+	  the release model archives).
+
 config HAVE_KERNEL_GZIP
 	bool

--
2.47.1