From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1E35A4369A; Sat, 12 Sep 2026 06:44:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789195491; cv=none; b=uPwhF4sB+5/bdohzOaeohnRphr1tAWA6uZW09pZAB2S0YiCOEDFRR3b7oN7O0nENo54zjdRRyElX7OJsLqEhIu5AtGTj5eWGTTOV3h1uBZSY6QL1lVfkz8/+0DgF0pAvdjbfVW4i2Q5YDLJfiIp7kb5rNtc8LwOkLOrcHBMaVO0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789195491; c=relaxed/simple; bh=tTNhIt/2Ld9YNVw0GTkyuXYb619+hSzvboXagJI0tSI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=knXrBgn7BgDYx9ngMwt6O1IC8wj2ZNBAgmC+2BaThC9zne0flzkeIz+taOS+GEm9kW6XQKcNuzo3bSklTVw3HOQUzUrpot3gSHc94lg0UcNGXuGD7wLBuHxYd0d6YvY9XTh11HRFzMabF648DVsBosY0zmD8pTz0nsGWjlnaYvA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=N2Bi/5zE; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="N2Bi/5zE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 43D3F1F000FF; Sat, 12 Sep 2026 06:44:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789195489; bh=KxaeJYmz4IdI2IIHmqchQdajHKy6Zs771P/FPguuVpg=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=N2Bi/5zE6FzP7AovVq0ROouwmcr2zpuMYJ/ewjhq59jZqei0S8amk2jxC+/ZgjWP3 AaptvB9VAe75PdStlXkwI7l0RBz8KeqgNl0kz8LaX+a7d1yKSshQvXTkAouGOOpcDC TRW3uqQNZuzDEMe3zlQPptV7QN2T6eFI88tLETBhUCOrdX8ZVRvO4lhBbrOURfPKfP kDNyvjYJbYySIJtdnNEwgU1kLZtxQxsTd4EQsWGkC5BWh2pEuCBuG2VqiU6REavtIb cGh8BTVzx6Xl6W38We3zbRZWqORKPwWtkab+G5KjlOinAcw5F32Mq3vdvWXFklGJDy 4fUlbAi0mw5jg== Date: Fri, 11 Sep 2026 23:44:37 -0700 From: Nathan Chancellor To: "Lorenzo Stoakes (ARM)" Cc: Florian Fainelli , Linus Torvalds , 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 , =?iso-8859-1?Q?Bj=F6rn?= Roy Baron , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , Daniel Almeida , Tamir Duberstein , Alexandre Courbot , Onur =?iso-8859-1?Q?=D6zkan?= , Jonathan Corbet , Randy Dunlap , 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 Subject: Re: [PATCH 00/23] kbuild: significantly speed up kernel builds Message-ID: <20260912064437.GB2002951@ax162> References: <20260908-build-speedup-v1-0-5dc1ac01672d@kernel.org> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Fri, Sep 11, 2026 at 12:28:34PM +0100, Lorenzo Stoakes (ARM) wrote: > On Wed, Sep 09, 2026 at 02:58:59PM -0700, Florian Fainelli wrote: > > On 9/8/26 13:55, Lorenzo Stoakes (ARM) wrote: > > > A typical kernel build consists of a frustratingly large amount of time > > > spent stuck in single-threaded bottlenecks. > > > > > > It turns out that there's a lot we can do about this and doing so > > > significantly impacts kernel build times. > > > > > > This series makes allmodconfig builds up to 36% faster, incremental builds > > > up to ~70% faster, and noop builds up to ~90% faster. > > > > > > Builds are faster across the board on every device I tested. > > > > > > Machines used for perf testing: > > > > > > * Threadripper - x86, AMD Threadripper 9980X, 64 cores, 128 threads > > > * EPYC - x86, 2 socket EPYC 9754, 256 cores, 512 threads > > > * M2 - arm64, 2022 M2 macbook pro, 8 cores, 8 threads > > > (4 perf, 4 efficiency) > > > > My AMD EPYC 9454P server shows an improvement in the order of 13% using the > > arm64's defconfig and make -j97. Thanks for doing this! > > Nice thanks! Good to confirm others are seeing the benefits :) I see similar gains on an 80-core Ampere Altra system 6h 21m 42s -> 5h 31m 15s (-13.22%) and a 32-core AMD system. 3h 38m 55s -> 3h 13m 18s (-11.7%) The build matrices were different between machines but it is good to see similar numbers across different environments. -- Cheers, Nathan