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 X-Spam-Level: X-Spam-Status: No, score=-5.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 112F7C07E9C for ; Mon, 12 Jul 2021 15:29:42 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id C8B0860FF1 for ; Mon, 12 Jul 2021 15:29:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C8B0860FF1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:40494 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m2xsL-0007Pj-1j for qemu-devel@archiver.kernel.org; Mon, 12 Jul 2021 11:29:41 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:56888) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m2xqZ-0005AL-74 for qemu-devel@nongnu.org; Mon, 12 Jul 2021 11:27:51 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:41202) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m2xqX-0008UW-B6 for qemu-devel@nongnu.org; Mon, 12 Jul 2021 11:27:50 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1626103668; 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:in-reply-to:in-reply-to: references:references; bh=Rh5WX9LrYkPEPy+1GpzfX7KMaLPc7svRZm3LQ4bmcrM=; b=VhsoP7KUmoWiGid2dcwnqsp0/jG75MrM2WBC90D0hMkHYe/i24LLOalPGHV1lBY6df0CpN D7Bq0XkymP4uCv7M6kf8uH1umVj/LIgbA+CMUGvx4IK8vCPv6srex8g2M8/w6p2XIPYVWo n/iqENuHgfW6T/2WCmScWdyy5fXpNr4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-586-1nekG3kyOv61vJA3oQ27kw-1; Mon, 12 Jul 2021 11:27:37 -0400 X-MC-Unique: 1nekG3kyOv61vJA3oQ27kw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7AE8D101C8D1; Mon, 12 Jul 2021 15:27:32 +0000 (UTC) Received: from redhat.com (ovpn-114-105.ams2.redhat.com [10.36.114.105]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AD96010550AF; Mon, 12 Jul 2021 15:27:29 +0000 (UTC) Date: Mon, 12 Jul 2021 16:27:26 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Andrew Jones Subject: Re: [RFC PATCH 1/6] machine: Set the value of maxcpus to match cpus if specified as zero Message-ID: References: <20210702100739.13672-1-wangyanan55@huawei.com> <20210702100739.13672-2-wangyanan55@huawei.com> <20210712145737.6gsawrmzbicgdevx@gator> MIME-Version: 1.0 In-Reply-To: <20210712145737.6gsawrmzbicgdevx@gator> User-Agent: Mutt/2.0.7 (2021-05-04) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline 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: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.699, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Eduardo Habkost , "Michael S . Tsirkin" , wanghaibin.wang@huawei.com, qemu-devel@nongnu.org, Yanan Wang , Igor Mammedov , yuzenghui@huawei.com, Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Jul 12, 2021 at 04:57:37PM +0200, Andrew Jones wrote: > On Fri, Jul 02, 2021 at 06:07:34PM +0800, Yanan Wang wrote: > > It is currently allowed to explicitly specified the topology parameters > > as 0 in the -smp cmdlines, such as -smp cpus=8,maxcpus=0,sockets=0. And > > for the values of cpus/sockets/cores/threads, we always determine that > > they are ommited if either set to 0 in the cmdline(e.g. sockets=0) or > > just not explicitly specified, then we compute the ommited values. > > > > We probably should also treat "maxcpus=0" as ommited and then set the > > value to match smp cpus. This makes cmdlines like "-smp 8, maxcpus=0" > > start to work as "-smp 8,maxcpus=8,sockets=8,cores=1,threads=1". > > > > Note that this patch won't affect any existing working cmdlines, but > > will allow configuration like "-smp cpus=n,maxcpus=0" to be valid. > > Personally, I'd rather see -smp cpus=n,sockets=0 become an error than to > "fix" -smp cpus=n,maxcpus=0. Yes, a value of 0 is not really something a user should ever be explicitly setting. It is purely an internal default that is used by QEMU to identify when it needs to auto-fill a value. A user should give a non-zero value, or omit the parameter entirely 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 :|