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 06934495503; Mon, 14 Sep 2026 17:50:20 +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=1789408221; cv=none; b=jNxzOtqcVwq8gAY7uzuaCyWfQ7UeLy6azo7wiADlQ9nMqtySfXLIzA9+14pCyrd/sZM6j/ka9AjjQg5qHhQtgU2vZcmoXC+o5YxD/C+xf/1G3ueNZmmqhu44olqimPTWYNJP4oW0ombtqZ272863g7zzJAWq9mJ8Y4IvqL9zzM8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789408221; c=relaxed/simple; bh=M6W30yQBqKEOsxjdNM6nYf5Fsz2YrwIgKsHWwkS2q/I=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=bOKx5xHplhX9yWC/WX8+I++hMtqe7JF5VMXMowr9VekGlOSmZRvViE7gIu+uxJnNLbiwoAzAOiiySI26TcRTUoUynn3ULwm/GvoFNldUsfL6qHCvr012tKygcZP2xwcKjm4lsFkfujAVZJxUFH1pwsB14iCoZWmdPS61Ub7ECNI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VzhPxfhr; 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="VzhPxfhr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D43CA1F000FF; Mon, 14 Sep 2026 17:50:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789408219; bh=e67qZ3QCn2L8qyNk+mdAvO35N1up2MXWgPivIgLpess=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=VzhPxfhrNGwUFy/l2g4I81wR8gE/J718KmUtsDuY/Uh6uBvIcRmhC5kc8HQt0wGA2 brpSBw73lF6qYAafp2WUtJU+3pucoX4YyQOUUaz9p4ygq6pNrUXZIMlbn4gYEXsohf bhstkaAV1y+GgJQzeladwBwQ4/xbaBeFfcoyFp0d/FdRjbO+4+HbiFSpuQoczjcEfw sBB7VEeWFU/QcEEEiSjFBYIgF300IaDeV+5AG/C7MAsOZOlCW1sCy8cOGc/cQRr7qT VvtxBqcopXv4rrKOLi6jWjhgFHFOUqy4WC82WwOIBmeDMhNiG05AJMZ2nPVLgOKFOD KhM7mBnSCMeuA== Date: Mon, 14 Sep 2026 10:50:19 -0700 From: Kees Cook To: "H. Peter Anvin" Cc: "Lorenzo Stoakes (ARM)" , 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, 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 21/21] kbuild: use pigz for gzip compression if available Message-ID: <202609141049.4B795585A@keescook> References: <20260914-build-speedup-v2-0-39817ec5db23@kernel.org> <20260914-build-speedup-v2-21-39817ec5db23@kernel.org> <202609140844.FA7E848A@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 Mon, Sep 14, 2026 at 09:49:50AM -0700, H. Peter Anvin wrote: > On September 14, 2026 9:39:07 AM PDT, Kees Cook wrote: > [...] > >diff --git a/tools/lib/python/jobserver.py b/tools/lib/python/jobserver.py > >index 0b1ffdf9f7a3..fc38c5020b22 100755 > >--- a/tools/lib/python/jobserver.py > >+++ b/tools/lib/python/jobserver.py > >@@ -29,6 +29,11 @@ $claim child to do the actual work. > > The end goal here is to keep the total number of build tasks under the > > limit established by the initial ``make -j$n_proc`` call. > > > >+Setting the ``SINGLE_THREADED`` environment variable skips the reservation > >+entirely and runs the command with ``PARALLELISM=1``. This is meant for callers > >+that run many short commands in parallel themselves, where each one should use > >+only the job slot it already holds. > >+ > > See: > > https://www.gnu.org/software/make/manual/html_node/POSIX-Jobserver.html#POSIX-Jobserver > > """ > >@@ -68,6 +73,13 @@ class JobserverExec: > > self.is_open = True # We only try once > > self.claim = None > > # > >+ # SINGLE_THREADED asks for no reservation at all: the command runs > >+ # with PARALLELISM=1, using only the slot its caller already holds. > >+ # > >+ if os.environ.get('SINGLE_THREADED'): > >+ self.claim = 1 > >+ return > >+ # > > # Check the make flags for "--jobserver=R,W" > > # Note that GNU Make has used --jobserver-fds and --jobserver-auth > > # so this handles all of them. > > > > If we are going to add dependencies, can we add *any* scripting language that is less stone tablet than POSIX awk? What are you referring to here? The jobserver logic is all Python. -- Kees Cook