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 BF0554457A6; Fri, 11 Sep 2026 11:25:56 +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=1789125968; cv=none; b=JrZij5PcGXWhYlPjf2VkH5e0N1l7VK6GUPS15ns0ipzUw3iAS1YBVAOtahqbr6qfGKKGyGIoHjv9VDU0eGtQ4yvf9uX0AD2uk5Mhfc28gaG+/K0vvIdKC4ko4kMQHjt/bc2LCyvoW1Apa9zP76osmXYC2E57aGHU9BFKZnXAANo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789125968; c=relaxed/simple; bh=limdG7iqTJH4ElLSnmTuuK3uee/BjGUPcvZqHysHW0g=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=JAMdnHRHik4DrOojwkruasrerbhoweZgG1HDfmIzEeQbaGAu95j0QDtBqJCwra/xhwmcOzjB+egjGEYDxfHF2Z+Za0dg8qbNGy6aVy8zOGuc+ao/eUYgV572gNDPPe2XSshwoPCAFOrIEju25K/C9jCGqnoFMB7pr12IgtKjQcs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ovdJkn1+; 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="ovdJkn1+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 58E071F000FF; Fri, 11 Sep 2026 11:25:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789125952; bh=limdG7iqTJH4ElLSnmTuuK3uee/BjGUPcvZqHysHW0g=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=ovdJkn1+n2Xa/HSnex3YjDFO2KbfhBxhc0ZdaLdHyehs1gqEr51Nzw2uwYipYaf+3 ShJd7JPRyZyDSCQfG1A/B1KlXaZIsedvL3nJMTxIhzKoTY8n59OEYX2qKsowcDVzF8 pu44Si6aULXKS8aAqrd9mM9S6BBNtnqbk81Eaaru496HCuu1b71N/gTwC45BRGxYg0 mj5FhIO3UbgDmDuo2E4Ezz5g76L6FGXyqaHbYCfq9tDi5eK3K0qQga4bPbTWgZmtub eLBHaP6WpPrv35lwy0BOxJ32kvrvGPCDN617FVQ1ORpnq/7MZ3nMUdH3GBDnOksEhS 6Wc0bT7UpLvlQ== Date: Fri, 11 Sep 2026 12:25:38 +0100 From: "Lorenzo Stoakes (ARM)" To: Nick Desaulniers Cc: Nathan Chancellor , Linus Torvalds , Nicolas Schier , 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> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Wed, Sep 09, 2026 at 03:09:10PM -0700, Nick Desaulniers wrote: > On Wed, Sep 9, 2026 at 7:17 AM Lorenzo Stoakes (ARM) wrote: > > > > On Tue, Sep 08, 2026 at 02:06:18PM -0700, Nick Desaulniers wrote: > > > It would be cool if your LLM could generate any visualizations of > > > what's going on during a build? Seeing what's serial vs parallelized > > > in perhaps useful. Particularly when you can compare the before vs > > > after. > > > > Great idea! > > > > I asked it to do exactly that, attached. Came out quite nice and sums it up > > nicely :) > > > > It also provided an ASCII version: > > unreadable, but the pictures you attached are worth a thousand words. :) Yeah I didn't think the ASCII was amazing either but fun that it tried ;) and yeah I was surprised at how nice the graphic came out...! > Particularly exciting are the speed ups to the usual edit+compile+run > loop. Yes! I never really expected that out of this! I mean I didn't think there'd be such a big speed up in general, though I expected at least to shave off a big chunk of the delta between compile + full build on a defconfig clean build. But the incremental/noop build improvements are really important to day-to-day use. > > For the blue graph (the top one, first), any idea what that dip in the > middle is? That's always what annoyed me. That's ld -r of vmlinux.o, then modpost and objtool which are critical path blockers on the rest of the build. Before the series that was 23 seconds for allmodconfig on the threadripper, now 7s :) There's still more objtool stuff that could be done that I opted not to do yet, it takes 6s to run so dominating. > -- > Thanks, > ~Nick Desaulniers -- Cheers, Lorenzo