From: Sami Tolvanen <samitolvanen@google.com> To: Masahiro Yamada <masahiroy@kernel.org>, Steven Rostedt <rostedt@goodmis.org> Cc: Will Deacon <will@kernel.org>, 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, x86@kernel.org, Sami Tolvanen <samitolvanen@google.com> Subject: [PATCH v6 12/25] kbuild: lto: limit inlining Date: Mon, 12 Oct 2020 17:31:50 -0700 [thread overview] Message-ID: <20201013003203.4168817-13-samitolvanen@google.com> (raw) In-Reply-To: <20201013003203.4168817-1-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 91cd6caefa6e..41b01248d400 100644 --- a/Makefile +++ b/Makefile @@ -894,6 +894,9 @@ 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 -- 2.28.0.1011.ga647a8990f-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> Cc: linux-arch@vger.kernel.org, x86@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, clang-built-linux@googlegroups.com, Sami Tolvanen <samitolvanen@google.com>, linux-pci@vger.kernel.org, Will Deacon <will@kernel.org>, linux-arm-kernel@lists.infradead.org Subject: [PATCH v6 12/25] kbuild: lto: limit inlining Date: Mon, 12 Oct 2020 17:31:50 -0700 [thread overview] Message-ID: <20201013003203.4168817-13-samitolvanen@google.com> (raw) In-Reply-To: <20201013003203.4168817-1-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 91cd6caefa6e..41b01248d400 100644 --- a/Makefile +++ b/Makefile @@ -894,6 +894,9 @@ 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 -- 2.28.0.1011.ga647a8990f-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:[~2020-10-13 2:42 UTC|newest] Thread overview: 188+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-10-13 0:31 [PATCH v6 00/25] Add support for Clang LTO Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 01/25] kbuild: preprocess module linker script Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 02/25] objtool: Add a pass for generating __mcount_loc Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-14 16:50 ` Ingo Molnar 2020-10-14 16:50 ` Ingo Molnar 2020-10-14 18:21 ` Peter Zijlstra 2020-10-14 18:21 ` Peter Zijlstra 2020-10-15 20:10 ` Josh Poimboeuf 2020-10-15 20:10 ` Josh Poimboeuf 2020-10-13 0:31 ` [PATCH v6 03/25] objtool: Don't autodetect vmlinux.o Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 04/25] tracing: move function tracer options to Kconfig Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 05/25] tracing: add support for objtool mcount Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 06/25] x86, build: use " Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 07/25] treewide: remove DISABLE_LTO Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-14 22:43 ` Kees Cook 2020-10-14 22:43 ` Kees Cook 2020-10-17 1:46 ` Masahiro Yamada 2020-10-17 1:46 ` Masahiro Yamada 2020-10-13 0:31 ` [PATCH v6 08/25] kbuild: add support for Clang LTO Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 09/25] kbuild: lto: fix module versioning Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 10/25] objtool: Split noinstr validation from --vmlinux Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 11/25] kbuild: lto: postpone objtool Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen [this message] 2020-10-13 0:31 ` [PATCH v6 12/25] kbuild: lto: limit inlining Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 13/25] kbuild: lto: merge module sections Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-14 22:49 ` Kees Cook 2020-10-14 22:49 ` Kees Cook 2020-10-20 16:42 ` Sami Tolvanen 2020-10-20 16:42 ` Sami Tolvanen 2020-10-20 16:42 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 14/25] kbuild: lto: remove duplicate dependencies from .mod files Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-14 22:50 ` Kees Cook 2020-10-14 22:50 ` Kees Cook 2020-12-03 17:59 ` Masahiro Yamada 2020-12-03 17:59 ` Masahiro Yamada 2020-12-03 18:47 ` Sami Tolvanen 2020-12-03 18:47 ` Sami Tolvanen 2020-12-03 18:47 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 15/25] init: lto: ensure initcall ordering Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 16/25] init: lto: fix PREL32 relocations Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-14 22:53 ` Kees Cook 2020-10-14 22:53 ` Kees Cook 2020-10-15 0:12 ` Jann Horn 2020-10-15 0:12 ` Jann Horn 2020-10-15 0:12 ` Jann Horn 2020-10-13 0:31 ` [PATCH v6 17/25] PCI: Fix PREL32 relocations for LTO Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-14 22:58 ` Kees Cook 2020-10-14 22:58 ` Kees Cook 2020-10-13 0:31 ` [PATCH v6 18/25] modpost: lto: strip .lto from module names Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 19/25] scripts/mod: disable LTO for empty.c Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 20/25] efi/libstub: disable LTO Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 21/25] drivers/misc/lkdtm: disable LTO for rodata.o Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:32 ` [PATCH v6 22/25] x86/asm: annotate indirect jumps Sami Tolvanen 2020-10-13 0:32 ` Sami Tolvanen 2020-10-13 0:32 ` Sami Tolvanen 2020-10-14 22:46 ` Kees Cook 2020-10-14 22:46 ` Kees Cook 2020-10-14 23:23 ` Jann Horn 2020-10-14 23:23 ` Jann Horn 2020-10-14 23:23 ` Jann Horn 2020-10-15 10:22 ` Peter Zijlstra 2020-10-15 10:22 ` Peter Zijlstra 2020-10-15 20:39 ` Josh Poimboeuf 2020-10-15 20:39 ` Josh Poimboeuf 2020-10-20 16:45 ` Sami Tolvanen 2020-10-20 16:45 ` Sami Tolvanen 2020-10-20 16:45 ` Sami Tolvanen 2020-10-20 18:52 ` Josh Poimboeuf 2020-10-20 18:52 ` Josh Poimboeuf 2020-10-20 19:24 ` Sami Tolvanen 2020-10-20 19:24 ` Sami Tolvanen 2020-10-20 19:24 ` Sami Tolvanen 2020-10-21 8:56 ` Peter Zijlstra 2020-10-21 8:56 ` Peter Zijlstra 2020-10-21 9:08 ` Peter Zijlstra 2020-10-21 9:08 ` Peter Zijlstra 2020-10-21 9:32 ` Peter Zijlstra 2020-10-21 9:32 ` Peter Zijlstra 2020-10-21 21:27 ` Josh Poimboeuf 2020-10-21 21:27 ` Josh Poimboeuf 2020-10-22 7:25 ` Peter Zijlstra 2020-10-22 7:25 ` Peter Zijlstra 2020-10-23 17:48 ` Sami Tolvanen 2020-10-23 17:48 ` Sami Tolvanen 2020-10-23 18:04 ` Nick Desaulniers 2020-10-23 18:04 ` Nick Desaulniers 2020-10-23 18:04 ` Nick Desaulniers 2020-10-21 15:01 ` Sami Tolvanen 2020-10-21 15:01 ` Sami Tolvanen 2020-10-21 15:01 ` Sami Tolvanen 2020-10-22 0:22 ` Sami Tolvanen 2020-10-22 0:22 ` Sami Tolvanen 2020-10-22 0:22 ` Sami Tolvanen 2020-10-23 17:36 ` Sami Tolvanen 2020-10-23 17:36 ` Sami Tolvanen 2020-11-09 23:11 ` Sami Tolvanen 2020-11-09 23:11 ` Sami Tolvanen 2020-11-09 23:11 ` Sami Tolvanen 2020-11-10 2:29 ` Josh Poimboeuf 2020-11-10 2:29 ` Josh Poimboeuf 2020-11-10 3:18 ` Nick Desaulniers 2020-11-10 3:18 ` Nick Desaulniers 2020-11-10 3:18 ` Nick Desaulniers 2020-11-10 4:48 ` Sami Tolvanen 2020-11-10 4:48 ` Sami Tolvanen 2020-11-10 4:48 ` Sami Tolvanen 2020-11-10 16:11 ` Josh Poimboeuf 2020-11-10 16:11 ` Josh Poimboeuf 2020-11-10 17:46 ` Josh Poimboeuf 2020-11-10 17:46 ` Josh Poimboeuf 2020-11-10 18:59 ` Sami Tolvanen 2020-11-10 18:59 ` Sami Tolvanen 2020-11-10 18:59 ` Sami Tolvanen 2020-11-13 19:54 ` Josh Poimboeuf 2020-11-13 19:54 ` Josh Poimboeuf 2020-11-13 20:24 ` Sami Tolvanen 2020-11-13 20:24 ` Sami Tolvanen 2020-11-13 20:24 ` Sami Tolvanen 2020-11-13 20:52 ` Josh Poimboeuf 2020-11-13 20:52 ` Josh Poimboeuf 2020-11-13 22:34 ` Josh Poimboeuf 2020-11-13 22:34 ` Josh Poimboeuf 2020-11-13 22:54 ` Sami Tolvanen 2020-11-13 22:54 ` Sami Tolvanen 2020-11-13 22:54 ` Sami Tolvanen 2020-11-13 22:56 ` Josh Poimboeuf 2020-11-13 22:56 ` Josh Poimboeuf 2020-11-13 23:31 ` Sami Tolvanen 2020-11-13 23:31 ` Sami Tolvanen 2020-11-13 23:31 ` Sami Tolvanen 2020-11-14 0:49 ` Josh Poimboeuf 2020-11-14 0:49 ` Josh Poimboeuf 2020-10-21 9:51 ` Peter Zijlstra 2020-10-21 9:51 ` Peter Zijlstra 2020-10-21 18:30 ` Josh Poimboeuf 2020-10-21 18:30 ` Josh Poimboeuf 2020-10-13 0:32 ` [PATCH v6 23/25] x86, vdso: disable LTO only for vDSO Sami Tolvanen 2020-10-13 0:32 ` Sami Tolvanen 2020-10-13 0:32 ` Sami Tolvanen 2020-10-13 0:32 ` [PATCH v6 24/25] x86, cpu: disable LTO for cpu.c Sami Tolvanen 2020-10-13 0:32 ` Sami Tolvanen 2020-10-13 0:32 ` Sami Tolvanen 2020-10-13 0:32 ` [PATCH v6 25/25] x86, build: allow LTO_CLANG and THINLTO to be selected Sami Tolvanen 2020-10-13 0:32 ` Sami Tolvanen 2020-10-13 0:32 ` Sami Tolvanen
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20201013003203.4168817-13-samitolvanen@google.com \ --to=samitolvanen@google.com \ --cc=clang-built-linux@googlegroups.com \ --cc=gregkh@linuxfoundation.org \ --cc=keescook@chromium.org \ --cc=kernel-hardening@lists.openwall.com \ --cc=linux-arch@vger.kernel.org \ --cc=linux-arm-kernel@lists.infradead.org \ --cc=linux-kbuild@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-pci@vger.kernel.org \ --cc=masahiroy@kernel.org \ --cc=ndesaulniers@google.com \ --cc=paulmck@kernel.org \ --cc=peterz@infradead.org \ --cc=rostedt@goodmis.org \ --cc=will@kernel.org \ --cc=x86@kernel.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.