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 C3E3B3B634E; Thu, 17 Sep 2026 17:36:34 +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=1789666596; cv=none; b=dV1KAPh9B9BjqZwDne0G9qzSd6wdNRZE0BlMGtM3yXoKOBjXGyjj4Dzs3IbIlebibzwxI7XgCYIZ2hISXnDNnGjc3zLdwkiwW33Kns4D3nqBteIzDHq0ml1AR3kPirktHk9dmqaWqhBHK6ZmPWd4YF7YI+hFsL2qh6lQ6y46/RQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789666596; c=relaxed/simple; bh=qwgEKnrrYNwqoGULkP2UgUlFnrQ7ncNkJf5Zc57zVR8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Lt3kVQn3v9piuOYsjjtvRmPwkXLguetjteoeZEGr3Hxn11jXJX0XzeXctMz7ID8+tM62Y4ysrmgBC0oqblil6ts5acuS51E5RjApqvPpy3KT1j+hWwKEqIImO4RfKEB9mhWj+1fEIK9CinVeMef5kNeHyBJTKOztV4BraziJZSo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=L1SJOQU/; 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="L1SJOQU/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9279B1F00893; Thu, 17 Sep 2026 17:36:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789666594; bh=jpy/yjEj4aDooyvICNTbdTtEq9cxmPnAGXVj2NFxZEs=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=L1SJOQU/7zwR2k1r6QQvFbRSb27nGC3gYV7j01JYcrg5+S9rs+/hLSEJEuJHxMTKJ 0fTVstSev5PwoNGUQ7/RLh3nO9HabXy9209Zn3Fcc1Yqqk30IqYiODTVrDJIB7nmYs qN5agK3p4SVYFaZTx5zNlmgZs17aBLbUtrKaXz1b8p1aJQS7wNBwY93H9vSNsQG58A Q9nW/cDcWh89WgjM99JxsOGYeAr4Va05Fm7DmR0ejnSn1DfF4etaEEcOAwoVPrCCdB TbrkgAjCCEz99A4aDim3hXRBkQWuEvUY7vuK90fmeIP0DsRTLi8zsgGMhM1mhnbaxP OkVSed7QJUM5Q== Date: Thu, 17 Sep 2026 18:36:18 +0100 From: "Lorenzo Stoakes (ARM)" To: Linus Torvalds Cc: 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?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 , Kees Cook , "Gustavo A. R. Silva" , 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 Subject: Re: [PATCH v3 00/20] kbuild: significantly speed up kernel builds Message-ID: References: <20260917-build-speedup-v3-0-9ecf4163ff36@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=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Sep 17, 2026 at 10:15:26AM -0700, Linus Torvalds wrote: > On Thu, 17 Sept 2026 at 09:06, Lorenzo Stoakes (ARM) wrote: > > > > == defconfig FULL build == > > > > before after delta > > ---------------------------------- > > Threadripper, gcc 32.5s 26.3s -6.1s (-19%) > > Threadripper, clang 34.5s 27.2s -7.3s (-21%) > > EPYC, gcc 28.7s 20.6s -8.1s (-28%) > > EPYC, clang 39.8s 32.2s -7.6s (-19%) > > M2, gcc 519.3s 512.4s -6.9s (-1%) > > M2, clang 634.5s 569.4s -65.1s (-10%) > > There's something odd going on with that M2 gcc build. Why is it such > an odd duck? Ugh dear lord I think the LLM somehow corrupted the numbers... Let me re-run those myself locally and come back with the actual times! (I didn't do an allmodconfig out of pure impatience but might take the time to do that too) > > Linus -- Cheers, Lorenzo