From: Sami Tolvanen <samitolvanen@google.com> To: Masahiro Yamada <masahiroy@kernel.org>, Steven Rostedt <rostedt@goodmis.org>, Will Deacon <will@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com>, Peter Zijlstra <peterz@infradead.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, "Paul E. McKenney" <paulmck@kernel.org>, Kees Cook <keescook@chromium.org>, Nick Desaulniers <ndesaulniers@google.com>, clang-built-linux@googlegroups.com, kernel-hardening@lists.openwall.com, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, Sami Tolvanen <samitolvanen@google.com> Subject: [PATCH v7 04/17] kbuild: lto: limit inlining Date: Wed, 18 Nov 2020 14:07:18 -0800 [thread overview] Message-ID: <20201118220731.925424-5-samitolvanen@google.com> (raw) In-Reply-To: <20201118220731.925424-1-samitolvanen@google.com> 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, defaulting to 100. Based on testing with arm64 defconfig, we found that a limit of 5 is a reasonable compromise between performance and binary size, reducing the size of a stripped vmlinux by 11%. Suggested-by: George Burgess IV <gbiv@google.com> Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> --- Makefile | 3 +++ 1 file changed, 3 insertions(+) diff --git a/Makefile b/Makefile index f27c0da5d05a..bee378f9fd50 100644 --- a/Makefile +++ b/Makefile @@ -901,6 +901,9 @@ else CC_FLAGS_LTO += -flto endif CC_FLAGS_LTO += -fvisibility=default + +# Limit inlining across translation units to reduce binary size +KBUILD_LDFLAGS += -mllvm -import-instr-limit=5 endif ifdef CONFIG_LTO -- 2.29.2.299.gdc1121823c-goog
WARNING: multiple messages have this Message-ID (diff)
From: Sami Tolvanen <samitolvanen@google.com> To: Masahiro Yamada <masahiroy@kernel.org>, Steven Rostedt <rostedt@goodmis.org>, Will Deacon <will@kernel.org> Cc: linux-arch@vger.kernel.org, Kees Cook <keescook@chromium.org>, "Paul E. McKenney" <paulmck@kernel.org>, kernel-hardening@lists.openwall.com, Peter Zijlstra <peterz@infradead.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, linux-kbuild@vger.kernel.org, Nick Desaulniers <ndesaulniers@google.com>, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen <samitolvanen@google.com>, Josh Poimboeuf <jpoimboe@redhat.com>, linux-arm-kernel@lists.infradead.org Subject: [PATCH v7 04/17] kbuild: lto: limit inlining Date: Wed, 18 Nov 2020 14:07:18 -0800 [thread overview] Message-ID: <20201118220731.925424-5-samitolvanen@google.com> (raw) In-Reply-To: <20201118220731.925424-1-samitolvanen@google.com> 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, defaulting to 100. Based on testing with arm64 defconfig, we found that a limit of 5 is a reasonable compromise between performance and binary size, reducing the size of a stripped vmlinux by 11%. Suggested-by: George Burgess IV <gbiv@google.com> Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> --- Makefile | 3 +++ 1 file changed, 3 insertions(+) diff --git a/Makefile b/Makefile index f27c0da5d05a..bee378f9fd50 100644 --- a/Makefile +++ b/Makefile @@ -901,6 +901,9 @@ else CC_FLAGS_LTO += -flto endif CC_FLAGS_LTO += -fvisibility=default + +# Limit inlining across translation units to reduce binary size +KBUILD_LDFLAGS += -mllvm -import-instr-limit=5 endif ifdef CONFIG_LTO -- 2.29.2.299.gdc1121823c-goog _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-11-18 22:07 UTC|newest] Thread overview: 134+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-11-18 22:07 [PATCH v7 00/17] Add support for Clang LTO Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` [PATCH v7 01/17] tracing: move function tracer options to Kconfig Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` [PATCH v7 02/17] kbuild: add support for Clang LTO Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 23:48 ` Nick Desaulniers 2020-11-18 23:48 ` Nick Desaulniers 2020-11-18 23:48 ` Nick Desaulniers 2020-11-20 16:23 ` Sami Tolvanen 2020-11-20 16:23 ` Sami Tolvanen 2020-11-20 16:23 ` Sami Tolvanen 2020-11-20 19:47 ` Kees Cook 2020-11-20 19:47 ` Kees Cook 2020-11-20 20:29 ` Nathan Chancellor 2020-11-20 20:29 ` Nathan Chancellor 2020-11-20 20:43 ` Kees Cook 2020-11-20 20:43 ` Kees Cook 2020-11-20 20:58 ` Sami Tolvanen 2020-11-20 20:58 ` Sami Tolvanen 2020-11-20 20:58 ` Sami Tolvanen 2020-11-20 23:59 ` Kees Cook 2020-11-20 23:59 ` Kees Cook 2020-11-21 1:46 ` Sami Tolvanen 2020-11-21 1:46 ` Sami Tolvanen 2020-11-21 1:46 ` Sami Tolvanen 2020-11-21 20:11 ` Kees Cook 2020-11-21 20:11 ` Kees Cook 2020-11-18 22:07 ` [PATCH v7 03/17] kbuild: lto: fix module versioning Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen [this message] 2020-11-18 22:07 ` [PATCH v7 04/17] kbuild: lto: limit inlining Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` [PATCH v7 05/17] kbuild: lto: merge module sections Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` [PATCH v7 06/17] kbuild: lto: remove duplicate dependencies from .mod files Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` [PATCH v7 07/17] init: lto: ensure initcall ordering Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` [PATCH v7 08/17] init: lto: fix PREL32 relocations Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` [PATCH v7 09/17] PCI: Fix PREL32 relocations for LTO Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` [PATCH v7 10/17] modpost: lto: strip .lto from module names Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` [PATCH v7 11/17] scripts/mod: disable LTO for empty.c Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` [PATCH v7 12/17] efi/libstub: disable LTO Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` [PATCH v7 13/17] drivers/misc/lkdtm: disable LTO for rodata.o Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` [PATCH v7 14/17] arm64: vdso: disable LTO Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-30 11:52 ` Will Deacon 2020-11-30 11:52 ` Will Deacon 2020-11-30 23:44 ` Sami Tolvanen 2020-11-30 23:44 ` Sami Tolvanen 2020-11-30 23:44 ` Sami Tolvanen 2020-11-18 22:07 ` [PATCH v7 15/17] KVM: arm64: disable LTO for the nVHE directory Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-23 10:21 ` David Brazdil 2020-11-23 10:21 ` David Brazdil 2020-11-23 18:34 ` Sami Tolvanen 2020-11-23 18:34 ` Sami Tolvanen 2020-11-23 18:34 ` Sami Tolvanen 2020-11-18 22:07 ` [PATCH v7 16/17] arm64: disable recordmcount with DYNAMIC_FTRACE_WITH_REGS Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-30 11:59 ` Will Deacon 2020-11-30 11:59 ` Will Deacon 2020-11-18 22:07 ` [PATCH v7 17/17] arm64: allow LTO_CLANG and THINLTO to be selected Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-18 22:07 ` Sami Tolvanen 2020-11-30 12:00 ` Will Deacon 2020-11-30 12:00 ` Will Deacon 2020-11-18 23:42 ` [PATCH v7 00/17] Add support for Clang LTO Nick Desaulniers 2020-11-18 23:42 ` Nick Desaulniers 2020-11-18 23:42 ` Nick Desaulniers 2020-11-20 10:29 ` Ard Biesheuvel 2020-11-20 10:29 ` Ard Biesheuvel 2020-11-20 10:29 ` Ard Biesheuvel 2020-11-20 20:19 ` Nick Desaulniers 2020-11-20 20:19 ` Nick Desaulniers 2020-11-20 20:19 ` Nick Desaulniers 2020-11-20 23:30 ` Ard Biesheuvel 2020-11-20 23:30 ` Ard Biesheuvel 2020-11-20 23:30 ` Ard Biesheuvel 2020-11-20 23:53 ` Nick Desaulniers 2020-11-20 23:53 ` Nick Desaulniers 2020-11-20 23:53 ` Nick Desaulniers 2020-11-21 7:35 ` Ard Biesheuvel 2020-11-21 7:35 ` Ard Biesheuvel 2020-11-21 7:35 ` Ard Biesheuvel 2020-11-21 11:40 ` Marc Zyngier 2020-11-21 11:40 ` Marc Zyngier 2020-11-21 3:14 ` Nathan Chancellor 2020-11-21 3:14 ` Nathan Chancellor 2020-11-20 4:04 ` Josh Poimboeuf 2020-11-20 4:04 ` Josh Poimboeuf 2020-11-20 20:25 ` Sami Tolvanen 2020-11-20 20:25 ` Sami Tolvanen 2020-11-20 20:25 ` Sami Tolvanen 2020-11-30 12:01 ` Will Deacon 2020-11-30 12:01 ` Will Deacon 2020-12-01 17:31 ` Kees Cook 2020-12-01 17:31 ` Kees Cook 2020-12-01 19:51 ` Nick Desaulniers 2020-12-01 19:51 ` Nick Desaulniers 2020-12-01 19:51 ` Nick Desaulniers 2020-12-01 21:38 ` Sami Tolvanen 2020-12-01 21:38 ` Sami Tolvanen 2020-12-01 21:38 ` Sami Tolvanen 2020-12-02 2:42 ` Masahiro Yamada 2020-12-02 2:42 ` Masahiro Yamada 2020-12-02 5:46 ` Sami Tolvanen 2020-12-02 5:46 ` Sami Tolvanen 2020-12-02 5:46 ` Sami Tolvanen 2020-12-02 18:54 ` Kees Cook 2020-12-02 18:54 ` Kees Cook
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