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 2D7C0372686; Mon, 14 Sep 2026 18:00:27 +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=1789408829; cv=none; b=OtnOSU+I53uBn3g2S6n0RlKYos9tyobyAtDQ2MWu5t5o4lOKsVM2HKVa5fPmVM66JsnY6jNNdrqX+1+cEJmZSGsqGquDiTyCF/iIRzibGc5HrreDlvHfNYSdVJvZs1bowNui58zV1nhGVWe7aZKwVsEgfP4OZ5Y3Y5gGWwkK/G0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789408829; c=relaxed/simple; bh=3+cqU+7jmuS3Vs/6V/yEs66Msl6H9pWzW4OWZhoiFlA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=PLlawIGd3hNFX3aGseGj9/gLxmr8TnNuoaJtdk+3IBsNLdh9jEn0Y0QNbiSl/guPC2Y+q8cP5ACwKA+LbTIs/xYrZBARroAQcD8jQx/Onrr0TjNkJm7B42VeBOnuUc47BBac8qwLV5luOLVTGw8WulqRZimuQWEfFOOEgOJ/vSk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ODZLqWaY; 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="ODZLqWaY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ACA2F1F000FF; Mon, 14 Sep 2026 18:00:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789408827; bh=NXbbt1iUoauMs+fLO9RzZKe19lkdH+Cr594Dnv6SVKQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=ODZLqWaYMLu9jeAppJFzYzDYbmDcJaGKcKFa9maRrc6IVgd+L6cfnoF+W8eb4TyYP VBuHxSYqLE0IKj4JLNPRHFMrajD3oqPR0Hli5WItdUw2yzXh5Fs1Z4z4Pk7XJ9ltAI lK9ar1JcXgrjYpleMvYP9gD/0aeoVIW9MHRWXi6H63l0hudVVU0iyu3NXARJ9wAmpg Ta47EUvAsb1kOr/kor+xnCOr7kifair0OdB5MBceq0djdxtfuvb8ncAwhxJHq7rgYO 0kgGIOgELBX9Z2bS9EIKYMvoB7j/ksCVXBCRHVF9/hI3IZndRa3knP+m3HefHNC/k0 1UIcN90vCw8zQ== Date: Mon, 14 Sep 2026 11:00:27 -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 v2 14/21] kbuild: batch module finalisation Message-ID: <202609141056.6AE2C82E@keescook> References: <20260914-build-speedup-v2-0-39817ec5db23@kernel.org> <20260914-build-speedup-v2-14-39817ec5db23@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: <20260914-build-speedup-v2-14-39817ec5db23@kernel.org> On Mon, Sep 14, 2026 at 10:22:13AM +0100, Lorenzo Stoakes (ARM) wrote: > Module finalisation on allmodconfig builds consists of a large number of > very short-lived jobs, and the make job dispatcher cannot possibly dispatch > jobs fast enough. This "cannot possibly" sounds like a weird LLM language intensifier. I'd rather a concrete description of the problem, not this kind of (redundant?) vagueness. > [...] > Fix this by splitting modules.order into chunks of 128 at a time, run in > parallel. Why "128"? This seems tied to the 128-thread test machine, but ends up getting hard-coded, but this choice of value needs some rationale, IMO. -- Kees Cook