This change limits function inlining across translation unit boundaries in order to reduce the binary size with LTO. The -import-instr-limit flag defines a size limit, as the number of LLVM IR instructions, for importing functions from other TUs. The default value is 100, and decreasing it to 5 reduces the size of a stripped arm64 defconfig vmlinux by 11%. Suggested-by: George Burgess IV <gbiv@xxxxxxxxxx> Signed-off-by: Sami Tolvanen <samitolvanen@xxxxxxxxxx> --- Makefile | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/Makefile b/Makefile index 3a7e5e5c17b9..ee66513a5b66 100644 --- a/Makefile +++ b/Makefile @@ -894,6 +894,10 @@ else CC_FLAGS_LTO_CLANG := -flto endif CC_FLAGS_LTO_CLANG += -fvisibility=default + +# Limit inlining across translation units to reduce binary size +LD_FLAGS_LTO_CLANG := -mllvm -import-instr-limit=5 +KBUILD_LDFLAGS += $(LD_FLAGS_LTO_CLANG) endif ifdef CONFIG_LTO -- 2.27.0.212.ge8ba1cc988-goog
