From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C0FB0C98302 for ; Wed, 23 Sep 2026 17:19:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:In-Reply-To:References:Message-Id :MIME-Version:Subject:Date:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=mw1yYjG/z97l+DeoZeXiF4dJJtu5rO6zN/fu8QpqcKE=; b=t1/ZMG0F+k/uI1 Ube3Av/+l1bCQ5CdzvcaWEwDocuU9mQzzF+QWfWvJ9ZXsZe0R/bM3KZ/am2Usm9QY1z6x+beXU00x BAr6dHI+4BVU4a4Vj7ZKXmM5spEV+cqXEUoFZ6KXlngsLXDz9KTzXbo3fFN5krOxEOphXUiFfduhE bQTdfB6O9bboCS7nys2NlTN0KjgF8TkzQnRJtmg1bDfkXrI/TPb7tgMZWE1rilY3bXvlw8yGiKtl1 +VYoe61zRi0tEdOo9TyKJqwgivypRaptj91tARau1Mq3Mzdc11GOMxUzWNhkKll2ebYc8AZg8G8Cm 7VP4vdFN7SP+Qd3tgJCQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x9Qd3-0000000904f-1PCf; Wed, 23 Sep 2026 17:19:33 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x9Qcz-0000000902e-10ku; Wed, 23 Sep 2026 17:19:29 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 02F344025D; Wed, 23 Sep 2026 17:19:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BE6B51F00893; Wed, 23 Sep 2026 17:19:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790183968; bh=Rr99y5k7+go2x3zYNVayaOE+WWHPPjrM2nwS9MChYr0=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=IdX2Jlv2q9z4c18/1je4x2BTqsOkbTh+Qltdmxsno7HZAIpDyNFFU0CFcnlFf95va 0k3k35Ze7aMEr7uQIIbNrS9W2tPkFiBb3GohT9Z7bTZs9YMoQFGnjbTjAuQABHMAPN nVq9sTjBGCox1kmTyBgfpNUHD0IjWyHKy8js1n08rN/dWVKvCdTNUnsPzmT63Ry1Pa uYM00Op9MLN/4mWp8vDLNJALjCIq3bmDEA29TE2UOTjd3Gbd5UVMATWLZMRlfmA5YX eDT12AYno1FVKahrIU3ZPiWwvb1wyXilIbovcfnNBbMXd0C4Wpa/X9ocugwn7VY7BF 2bSTibPzT/ALw== From: "Lorenzo Stoakes (ARM)" Date: Wed, 23 Sep 2026 18:17:54 +0100 Subject: [PATCH v4 05/22] kbuild: do not sort nm output where the order is irrelevant MIME-Version: 1.0 Message-Id: <20260923-build-speedup-v4-5-73128809a4a4@kernel.org> References: <20260923-build-speedup-v4-0-73128809a4a4@kernel.org> In-Reply-To: <20260923-build-speedup-v4-0-73128809a4a4@kernel.org> To: Linus Torvalds , Nathan Chancellor , Nicolas Schier , Nick Desaulniers , Bill Wendling , Justin Stitt , Masahiro Yamada , Alexey Gladkov , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Arnd Bergmann , Catalin Marinas , Will Deacon , Mark Rutland , Ard Biesheuvel , Ilias Apalodimas , Josh Poimboeuf , Peter Zijlstra , Miguel Ojeda , Boqun Feng , Gary Guo , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , Daniel Almeida , Tamir Duberstein , Alexandre Courbot , =?utf-8?q?Onur_=C3=96zkan?= , Jonathan Corbet , Randy Dunlap , Kees Cook , "Gustavo A. R. Silva" Cc: linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, linux-riscv@lists.infradead.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-efi@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-doc@vger.kernel.org, Jens Axboe , linux-hardening@vger.kernel.org, Petr Pavlu , "Lorenzo Stoakes (ARM)" , Nicolas Schier X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=5086; i=ljs@kernel.org; h=from:subject:message-id; bh=MLUfGBmyVIicidewYxyd0wSyemJP9IVOSHNNzSMSLro=; b=owGbwMvMwCV2fu7ZrsZH9SKMp9WSGLK2cF5ac2pzhUtH/aYM2S3FiwqvzVXaJ/2sVGr9XqPy4 qR/Nxb86ChlYRDjYpAVU2R5/kV8f5BI2LzOC/5uMHNYmUCGMHBxCsBE4lcx/NPbOHNVy0KPdcrM FhdEbFuTnSYx2lwPe/burntDcOmqr7IMf3j8l79wD1qtMuF//kzbBdqmV7+1ladn8B5m2f+lYCL /XAYA X-Developer-Key: i=ljs@kernel.org; a=openpgp; fpr=E7F417BF5214569E89D04F46CF9DCD8A81E27F14 X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Unless instructed otherwise, nm sorts by name. There are places where this is unnecessary - an invocation from scripts/sorttable every vmlinux link, scripts/check-function-names.sh run after every vmlinux.o link, and the x86 VOFFSET and ZOFFSET listings between vmlinux and bzImage. Both GNU nm and llvm-nm accept the same '-p' parameter to disable sorting in these instances, so use that to prevent this unnecessary work. Each nm run on its own, x86-64, median of 5: GNU nm 2.47 llvm-nm 22 before after delta before after delta defconfig sorttable, nm -S vmlinux 0.080s 0.039s -0.041s 0.265s 0.113s -0.152s check-function-names.sh 0.072s 0.033s -0.039s 0.244s 0.102s -0.142s VOFFSET 0.077s 0.034s -0.043s 0.261s 0.113s -0.148s ZOFFSET 0.007s 0.005s -0.002s 0.005s 0.005s 0.000s TOTAL -0.125s -0.442s allmodconfig sorttable, nm -S vmlinux 0.156s 0.063s -0.093s 0.539s 0.223s -0.316s check-function-names.sh 0.149s 0.054s -0.095s 0.537s 0.217s -0.320s VOFFSET 0.146s 0.052s -0.094s 0.524s 0.221s -0.303s ZOFFSET 0.007s 0.005s -0.002s 0.006s 0.004s -0.002s TOTAL -0.284s -0.941s llvm-nm appears to be a lot slower than GNU nm, so these builds naturally improve the most. The four run one after another in the serial tail of every build that links vmlinux so impact kernel builds directly. In an allmodconfig the decompressor is built in parallel while the modules, so only the two before the vmlinux link contribute to build time. The build outputs remain unchanged. Whole build, 128-thread Threadripper 9980X, best of N runs: before after delta --------------------------------- x86 defconfig, touch mm/vma.c, gcc 9.7s 9.5s -0.18s (-2%) x86 defconfig, touch mm/vma.c, clang 9.3s 9.0s -0.27s (-3%) x86 defconfig, clean, gcc 30.3s 30.1s -0.16s (-1%) x86 defconfig, clean, clang 31.7s 31.2s -0.55s (-2%) x86 allmodconfig, touch mm/vma.c, clang 36.4s 35.8s -0.67s (-2%) Assisted-by: LLM Reviewed-by: Nicolas Schier Reviewed-by: Kees Cook Signed-off-by: Lorenzo Stoakes (ARM) --- arch/x86/boot/Makefile | 2 +- arch/x86/boot/compressed/Makefile | 2 +- scripts/check-function-names.sh | 3 ++- scripts/link-vmlinux.sh | 2 +- 4 files changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile index 3f9fb3698d66..4a9bce32586d 100644 --- a/arch/x86/boot/Makefile +++ b/arch/x86/boot/Makefile @@ -74,7 +74,7 @@ SETUP_OBJS = $(addprefix $(obj)/,$(setup-y)) sed-zoffset := -e 's/^\([0-9a-fA-F]*\) [a-zA-Z] \(startup_32\|efi.._stub_entry\|efi\(32\)\?_pe_entry\|input_data\|kernel_info\|_end\|_ehead\|_text\|_e\?data\|_e\?sbat\|z_.*\)$$/\#define ZO_\2 0x\1/p' quiet_cmd_zoffset = ZOFFSET $@ - cmd_zoffset = $(NM) $< | sed -n $(sed-zoffset) > $@ + cmd_zoffset = $(NM) -p $< | sed -n $(sed-zoffset) > $@ targets += zoffset.h $(obj)/zoffset.h: $(obj)/compressed/vmlinux FORCE diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 06934f9691d6..6ec5e031db1d 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -76,7 +76,7 @@ HOST_EXTRACFLAGS += -I$(srctree)/tools/include sed-voffset := -e 's/^\([0-9a-fA-F]*\) [ABbCDGRSTtVW] \(_text\|__start_rodata\|_sinittext\|__inittext_end\|__bss_start\|_end\)$$/\#define VO_\2 _AC(0x\1,UL)/p' quiet_cmd_voffset = VOFFSET $@ - cmd_voffset = $(NM) $< | sed -n $(sed-voffset) > $@ + cmd_voffset = $(NM) -p $< | sed -n $(sed-voffset) > $@ targets += ../voffset.h diff --git a/scripts/check-function-names.sh b/scripts/check-function-names.sh index 08071133e5a5..94883e690627 100755 --- a/scripts/check-function-names.sh +++ b/scripts/check-function-names.sh @@ -13,7 +13,8 @@ if [ ! -f "$objfile" ]; then exit 1 fi -bad_symbols=$(${NM:-nm} "$objfile" | awk '$2 ~ /^[TtWw]$/ {print $3}' | grep -E '^(startup|exit|split|unlikely|hot|unknown)(\.|$)') +bad_symbols=$(${NM:-nm} -p "$objfile" | awk '$2 ~ /^[TtWw]$/ {print $3}' | + grep -E '^(startup|exit|split|unlikely|hot|unknown)(\.|$)') if [ -n "$bad_symbols" ]; then echo "$bad_symbols" | while read -r sym; do diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index e88604150d2c..970ca10f8fa9 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -161,7 +161,7 @@ mksysmap() sorttable() { - ${NM} -S ${1} > .tmp_vmlinux.nm-sort + ${NM} -p -S ${1} > .tmp_vmlinux.nm-sort ${objtree}/scripts/sorttable -s .tmp_vmlinux.nm-sort ${1} } -- 2.55.0 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv