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 E3F343C988B; Sun, 20 Sep 2026 03:48:24 +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=1789876106; cv=none; b=NA/LeuJsWEIPD2wokqvLxV7hFQaQgPESwDygfcv8w3+0XIBXfZMbwsaRJtFfb/3Koum5EbX+YS1L4PBR+s7bY1BH3OvGTvn1ovHTl7r6BjHhE200XJX3PZgogJg0RqWI7BpbSDZoi+LueQNCuSRsJ+x0WqD7V/s8JxCwqy5HnNs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789876106; c=relaxed/simple; bh=GSrtFVQAoq72BuT4l8bSIy6B2kt0Hd5qAgqf+SK4zMM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Ajp3i2J+MOgHiq4Hmw3p5FHfTHG4Z1MD8VAiCwaZr77KBEIP5rC6LU/PzuajvJCiTMDHwFxJhPz23e/xPVGoSiSBqI72HkUVFBQ60/fdE/IEDvL8iukunYpNEh/BgAqh8KkHYEgEtIRzxyTuF4xsVJNMHFvmSxPow2Z0IEO+jWs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YBC6aBoZ; 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="YBC6aBoZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C45C01F000FF; Sun, 20 Sep 2026 03:48:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789876104; bh=ybCr0oF8quCv/avwZgHBTOG1l69Dfvx6Rf/qRs6G0NM=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=YBC6aBoZFH8ZoVIjcCysvgKQWPCeAZnK7xSXqRi8+dyWiyNvuz6IjqFWVKI+gEzA3 oaMZt+GfiWWPwZO+L7WtXR6zTVPWm8J5aEQddxqJ9e8w9wdXf9cgyQkwYsShqX/3y3 N6q33sbNYcxGvAtrsYo3EEQ1xP8Sx7eo8YiTsMCwsBDDR8h5oUZoUzzWD7hn+yryq/ dmoy7MMUFxy9hhJgZ1IuBPQFuWfx1BGqdpXi0ELNTQT7jOC3pbUc6TgXZiNsFdvHgO 2IPsOuX8fnt1Lpf/zBLFIb5c3OeIqw4T36I3/T9Np3Fk0ATdmUGrQeHxMxPs1dTCJs 9OLkkJAmVBHTA== Date: Sat, 19 Sep 2026 20:48:24 -0700 From: Kees Cook To: "Lorenzo Stoakes (ARM)" Cc: 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 , =?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 , "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 09/20] kbuild: implement and use depcheck to check dependency timestamps Message-ID: <202609192047.17BD9B1F@keescook> References: <20260917-build-speedup-v3-0-9ecf4163ff36@kernel.org> <20260917-build-speedup-v3-9-9ecf4163ff36@kernel.org> <202609171117.35BFDCC13@keescook> 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 Sat, Sep 19, 2026 at 05:57:36PM +0100, Lorenzo Stoakes (ARM) wrote: > On Thu, Sep 17, 2026 at 11:42:50AM -0700, Kees Cook wrote: > > On Thu, Sep 17, 2026 at 05:06:19PM +0100, Lorenzo Stoakes (ARM) wrote: > > > [...] > > > +static bool next_line(const char **pos, const char *end, struct line *line) > > > > There is a lot of string handling in here. I know you're going for speed, > > but it just feels like a python script doing all this would be much more > > readable without wrecking speed compared to C much. Yes, C will win out, > > but the maintainability of this helper does not fill me with joy. :P > > Well I had the LLM look at that and for an allmodconfig python's startup time > would take 40s of CPU time _alone_ and it'd kill the no op improvement. So C it > has to be :) Yikes, that's huge. C it is. ;) -- Kees Cook