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=-5.0 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 1B6D3C2B9F4 for ; Tue, 22 Jun 2021 10:25:00 +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 CF563613AE for ; Tue, 22 Jun 2021 10:24:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CF563613AE 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]:40602 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lvdaU-00080d-TL for qemu-devel@archiver.kernel.org; Tue, 22 Jun 2021 06:24:59 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45206) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lvdUS-00049J-CE for qemu-devel@nongnu.org; Tue, 22 Jun 2021 06:18:44 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:47903) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lvdUP-0006gs-AS for qemu-devel@nongnu.org; Tue, 22 Jun 2021 06:18:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1624357120; 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=gzrImPinhRNlxdci63CYV4SVhoeg6XtsX8beB1ydNkk=; b=MY+vSs6y6XesJO5S830wptl9xvsA/DRZ+wQ4n4h7QHu+aKlpht48ILrnR6P/PB/bnLA/GM P5QHVAQWc4yCTaYQ+bRIdItzDYTBNjbULGXefH/CJYHjuCOlSdgB5ohFqZ7YPGSJwEtchF aqyw1aIppnof3R+3+LUXTlDsJJ7E2PI= 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-197-97JpW901OT-AojPhjsJ9OA-1; Tue, 22 Jun 2021 06:18:24 -0400 X-MC-Unique: 97JpW901OT-AojPhjsJ9OA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 83A55101C8A8; Tue, 22 Jun 2021 10:18:22 +0000 (UTC) Received: from redhat.com (ovpn-114-176.ams2.redhat.com [10.36.114.176]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C0B0E5C1CF; Tue, 22 Jun 2021 10:18:12 +0000 (UTC) Date: Tue, 22 Jun 2021 11:18:09 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Yanan Wang Subject: Re: [RFC PATCH v4 0/7] hw/arm/virt: Introduce cpu topology support Message-ID: References: <20210622093413.13360-1-wangyanan55@huawei.com> MIME-Version: 1.0 In-Reply-To: <20210622093413.13360-1-wangyanan55@huawei.com> User-Agent: Mutt/2.0.7 (2021-05-04) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 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=216.205.24.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.373, 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=unavailable 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: Barry Song , Peter Maydell , Andrew Jones , "Michael S . Tsirkin" , wanghaibin.wang@huawei.com, qemu-devel@nongnu.org, yangyicong@huawei.com, Shannon Zhao , qemu-arm@nongnu.org, Alistair Francis , prime.zeng@hisilicon.com, Paolo Bonzini , yuzenghui@huawei.com, Igor Mammedov , zhukeqian1@huawei.com, David Gibson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, Jun 22, 2021 at 05:34:06PM +0800, Yanan Wang wrote: > Hi, > > This is v4 of the series [1] that I posted to introduce support for > generating cpu topology descriptions to guest. Comments are welcome! > > Description: > Once the view of an accurate virtual cpu topology is provided to guest, > with a well-designed vCPU pinning to the pCPU we may get a huge benefit, > e.g., the scheduling performance improvement. See Dario Faggioli's > research and the related performance tests in [2] for reference. So here > we go, this patch series introduces cpu topology support for ARM platform. > > In this series, instead of quietly enforcing the support for the latest > machine type, a new parameter "expose=on|off" in -smp command line is > introduced to leave QEMU users a choice to decide whether to enable the > feature or not. This will allow the feature to work on different machine > types and also ideally compat with already in-use -smp command lines. > Also we make much stricter requirement for the topology configuration > with "expose=on". Seeing this 'expose=on' parameter feels to me like we're adding a "make-it-work=yes" parameter. IMHO this is just something that should be done by default for the current machine type version and beyond. I don't see the need for a parameter to turnthis on, especially since it is being made architecture specific. 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 :|