From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B0F0DC38145 for ; Wed, 7 Sep 2022 09:13:59 +0000 (UTC) Received: from localhost ([::1]:58528 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oVr8A-0007C9-Gv for qemu-devel@archiver.kernel.org; Wed, 07 Sep 2022 05:13:58 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:50030) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oVqun-0006Pi-Vi for qemu-devel@nongnu.org; Wed, 07 Sep 2022 05:00:14 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:40981) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oVqug-0004L8-LZ for qemu-devel@nongnu.org; Wed, 07 Sep 2022 05:00:07 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1662541201; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ogj31i8gWK7f9Zz/ZHZgMdJjp+V5M0eda1f3riENlG0=; b=bPDUooEmU05QMX3YrGZWOdPitDVuz6eWWk8n6PIkgUAQ+J3H+nQtSXl3TWAiDaj23hbRpe /73r9N3Uyy6+xF/Me/Hh8wi7TmoWNBZ+QRU05d68Z486pU63LueR+jkQJ0KypyI+TQ0Yjm aqcOaPW1E9W5dQo75YUby2Tndpp4Yms= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-358-DoX5M4eGMC6yBTAK6IBsdQ-1; Wed, 07 Sep 2022 04:59:57 -0400 X-MC-Unique: DoX5M4eGMC6yBTAK6IBsdQ-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 79AD33806706; Wed, 7 Sep 2022 08:59:57 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.193.166]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4A278492C3B; Wed, 7 Sep 2022 08:59:57 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 6DBF521E6900; Wed, 7 Sep 2022 10:59:54 +0200 (CEST) From: Markus Armbruster To: Peter Maydell Cc: Daniel P. =?utf-8?Q?Berrang=C3=A9?= , Claudio Fontana , qemu-devel Subject: Re: sphinx-build is really slow, any way to improve that? References: <53b94520-f02b-aef5-b372-0460531b566f@suse.de> Date: Wed, 07 Sep 2022 10:59:54 +0200 In-Reply-To: (Peter Maydell's message of "Tue, 6 Sep 2022 14:41:13 +0100") Message-ID: <87leqvzhit.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.85 on 10.11.54.10 Received-SPF: pass client-ip=170.10.133.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Peter Maydell writes: > On Tue, 6 Sept 2022 at 08:55, Daniel P. Berrang=C3=A9 wrote: >> >> On Mon, Sep 05, 2022 at 10:21:55PM +0100, Peter Maydell wrote: >> > On Mon, 5 Sept 2022 at 20:51, Claudio Fontana wrote: >> > > when I build qemu, there is a lot of time spent at the end of the bu= ild where one cpu goes 100% on sphinx-build. >> > > >> > > Is there some way to parallelize that? It seems it is the current bo= ttleneck for rebuilds for me.. >> > >> > It's a big fat python program, so I suspect not, but >> > maybe I'm wrong. >> >> It annoys me too and I've had a look at what it is doing in the past and >> failed to find an obvious way to improve it. I fear this could be an >> inherant limitation of the way we use sphinx to build the docs as a >> complete manual, as compared to say treating each docs source file as >> a distinct standalone web page. > > IIRC sphinx really really wants to process the whole document tree > in one go. You can see this in the way that for example the > HTML build process creates HTML files for the top-level rst > files that are supposed to be only for the manpage -- it will > suck in and process everything, not just the files reachable > via whatever top level file you point it at. How do other projects deal with the resulting slowness? Could we avoid rerunning sphinx-build when documentation hasn't changed?