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 45DE3C77B61 for ; Thu, 27 Apr 2023 17:34:22 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ps5VJ-0005DE-L8; Thu, 27 Apr 2023 13:34:02 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ps5VD-0005Cq-MJ for qemu-devel@nongnu.org; Thu, 27 Apr 2023 13:33:57 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ps5V8-0001fa-6z for qemu-devel@nongnu.org; Thu, 27 Apr 2023 13:33:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1682616827; h=from:from:reply-to: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=NxxT+TeYXBgs0TUaE3Gu5jIOfQv1GAqMfv0VPNw7xz0=; b=Pig6mRWyhaunbBlPFuWm/+beDehnXUZKhaOEQgZ4kokQ9sPLDRHCiPqjOGhmOgoHsXR2yh nTNvVgayrfHzf3jM9yiGfyWk9UMpBOwtwp0nWj7iY/2FcE6YPt66QK2sPcTxeqPt33lLLx 2XloLetexiZaIBZtaLBk8VdS6DJK6ak= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-160-InD75eZlPpegyAlfLpZXgg-1; Thu, 27 Apr 2023 13:33:44 -0400 X-MC-Unique: InD75eZlPpegyAlfLpZXgg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 38CAB858F0E; Thu, 27 Apr 2023 17:33:44 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.44]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 342C563F4D; Thu, 27 Apr 2023 17:33:43 +0000 (UTC) Date: Thu, 27 Apr 2023 18:33:40 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Fabiano Rosas Cc: qemu-devel@nongnu.org, Paolo Bonzini , Thomas Huth , =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , Peter Maydell Subject: Re: [PATCH v2] meson: Pass -j option to sphinx Message-ID: References: <20230427172516.19003-1-farosas@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20230427172516.19003-1-farosas@suse.de> User-Agent: Mutt/2.2.9 (2022-11-12) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -22 X-Spam_score: -2.3 X-Spam_bar: -- X-Spam_report: (-2.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.171, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Thu, Apr 27, 2023 at 02:25:16PM -0300, Fabiano Rosas wrote: > Save a bit of build time by passing the number of jobs option to > sphinx. > > We cannot use the -j option from make because meson does not support > setting build time parameters for custom targets. Use nproc instead or > the equivalent sphinx option "-j auto", if that is available. > > Also make sure our plugins support parallelism and report it properly > to sphinx. Particularly, implement the merge_domaindata method in > DBusDomain that is used to merge in data from other subprocesses. > > before: > $ time make man html > ... > [1/2] Generating docs/QEMU manual with a custom command > [2/2] Generating docs/QEMU man pages with a custom command > > real 0m43.157s > user 0m42.642s > sys 0m0.576s > > after: > $ time make man html > ... > [1/2] Generating docs/QEMU manual with a custom command > [2/2] Generating docs/QEMU man pages with a custom command > > real 0m25.014s > user 0m51.288s > sys 0m2.085s On my 12 CPU laptop I see a similar magnitude benefit - about 20 seconds is cut from the docs build time - 50 down to 30 secs. Watching the CPU usage I see sphinx is not very good at keeping all CPUs busy. For perhaps 2 seconds I'll see 8 sphinx processes burning CPUs, but the majority of the time it'll only be 1 or 2 sphinx processes. IOW, we do get a benefit, but it is not nearly as good as one might hope for given the number of CPUs potentially available. > Signed-off-by: Fabiano Rosas > --- > docs/meson.build | 12 ++++++++++++ > docs/sphinx/dbusdomain.py | 4 ++++ > docs/sphinx/fakedbusdoc.py | 5 +++++ > docs/sphinx/qmp_lexer.py | 5 +++++ > 4 files changed, 26 insertions(+) Tested-by: Daniel P. Berrangé > > diff --git a/docs/meson.build b/docs/meson.build > index f220800e3e..9e4bed6fa0 100644 > --- a/docs/meson.build > +++ b/docs/meson.build > @@ -10,6 +10,18 @@ if sphinx_build.found() > SPHINX_ARGS += [ '-W', '-Dkerneldoc_werror=1' ] > endif > > + sphinx_version = run_command(SPHINX_ARGS + ['--version'], > + check: false).stdout().split()[1] > + if sphinx_version.version_compare('>=5.1.2') > + SPHINX_ARGS += ['-j', 'auto'] > + else > + nproc = find_program('nproc') > + if nproc.found() > + jobs = run_command(nproc, check:false).stdout() > + SPHINX_ARGS += ['-j', jobs] > + endif > + endif ANy reason for check: false in these 2 run_command calls ? They'll both return 0 on success, so I would have though 'check: true' was more robust at error reporting ? With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|