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 43BAF31E858; Sun, 13 Sep 2026 16:27:40 +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=1789316861; cv=none; b=XMRAPv0pwjs3hZyd4AKCJoq/+Nz+PRIM4+u0BKXLFzPPnXIqycmcLtX0bfEWUA04BFqSCxToklijdCvXRQLlcE1zJnBseG1U3L5K46iwnJsRhsJwiH9U6lHXJCwmQNXgVDGX0VMaGBj3mNOUlRQMprhyYOS5RKXd785F2fx6oyI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789316861; c=relaxed/simple; bh=O/e6CfAS9RNEQqaHGYKaIdIIqALc4dIkdCyGZZYAd/M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kfKHsjgqdZ7hANXu4s2o/+LGrxSwEo6Ibj4OWrYH5OAvzn/FEDbznzC/8iHNsO5I8bX1IyDNdfMGrVsYZ/V/s7iZEbouoDtGJDvI3ZRMH8Vpi0R/+gTD+tugM/VusEy+Telv1f0U7onnXg8zfLLfumztaBILax1BXys1nwgWS2Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=S1T5EvtI; 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="S1T5EvtI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 049D11F000FF; Sun, 13 Sep 2026 16:27:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789316859; bh=A34XyoS7noGhiNdA0/AU98h7WFkZVbNZsRjK3AbUsrc=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=S1T5EvtIkopSpnh+GD+zu8g4AJduDGp4esWSo99SyJNqgNpcU1UVbfy4cZhHMNB0i LHSz2WYMWir3RbcYjKe/iPRdEa+j0hhJUnM/Y2wcjhDmtHgIgTt+SMBRaE+EKNHur3 tISbPphKo+YKH1t2eW+TWtim9ts6B0icsa2UF204ftWrTdf6+U35adxnq+u1RGPUgE 6+NK6KcfQtUATUK4NjWOw4HkQ4OuKPR6xoMhT8hU+MSm/FZJUMH6cEFCc/BLLAKkax hFL/+6sEynaqO3hN0xSh2fX2eW7avxvzNLOpeFKX5TxXn2w7A57CIRGSGoV88TZ2qI B5QZhmpvaMAEQ== Date: Sun, 13 Sep 2026 17:27:25 +0100 From: "Lorenzo Stoakes (ARM)" To: Nathan Chancellor 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 , =?utf-8?B?QmrDtnJu?= Roy Baron , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , Daniel Almeida , Tamir Duberstein , Alexandre Courbot , Onur =?utf-8?B?w5Z6a2Fu?= , 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: References: <20260908-build-speedup-v1-0-5dc1ac01672d@kernel.org> <20260912064437.GB2002951@ax162> Precedence: bulk X-Mailing-List: linux-doc@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: <20260912064437.GB2002951@ax162> On Fri, Sep 11, 2026 at 11:44:37PM -0700, Nathan Chancellor wrote: > 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. Nice, yes for sure! > > -- > Cheers, > Nathan -- Cheers, Lorenzo