From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) by mx.groups.io with SMTP id smtpd.web10.10.1614101370558490699 for ; Tue, 23 Feb 2021 09:29:31 -0800 Authentication-Results: mx.groups.io; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=DPaQWShj; spf=pass (domain: redhat.com, ip: 63.128.21.124, mailfrom: lersek@redhat.com) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614101369; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=aJn1TW5bAVPQFSANgyaL5d5OlIxzfolJSu1SkNYg/2k=; b=DPaQWShjvNz/1JtB+x5aPGKNYnGuYbKyTr9WzDaSBw3BlO97N+goOrxkcUInPSMHk2ZFJY bXQs/IjEcjJ8LPKiEiOVcjFSfQu/xCAebHqm0C2WzoMq62jQerz7mW+jGMYHsKJWd2+Nyv xoemubNPcZ93S72SkrIEGwogGF6Bzhs= 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-362-r6kt5Jk_P3-VXYacoU9jaQ-1; Tue, 23 Feb 2021 12:29:26 -0500 X-MC-Unique: r6kt5Jk_P3-VXYacoU9jaQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BAAAE801978; Tue, 23 Feb 2021 17:29:24 +0000 (UTC) Received: from lacos-laptop-7.usersys.redhat.com (ovpn-113-109.ams2.redhat.com [10.36.113.109]) by smtp.corp.redhat.com (Postfix) with ESMTP id DDDA61899A; Tue, 23 Feb 2021 17:29:23 +0000 (UTC) Subject: Re: [edk2-devel] MP Services Protocol : Support Hyper threading or not To: devel@edk2.groups.io, fanjianfeng@byosoft.com.cn, tigerliu References: <03f9e675800143189bc59fab08865256@zhaoxin.com> <581d5952-32b2-56e3-30d5-7f7f24039fa0@redhat.com> <2021022309172935358813@byosoft.com.cn> From: "Laszlo Ersek" Message-ID: <7af93e4d-8855-d841-3773-ce509705622d@redhat.com> Date: Tue, 23 Feb 2021 18:29:22 +0100 MIME-Version: 1.0 In-Reply-To: <2021022309172935358813@byosoft.com.cn> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=lersek@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit On 02/23/21 02:17, fanjianfeng@byosoft.com.cn wrote: > " Will EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() make all 8 logical cores do some tasks simultaneously?" > > All APs logical processors excute AP task, not including BSP. Acutally the answer is 7. Good point :) Thanks Laszlo > > Jeff > > From: Laszlo Ersek > Date: 2021-02-22 18:39 > To: devel; tigerliu > Subject: Re: [edk2-devel] MP Services Protocol : Support Hyper threading or not > On 02/22/21 08:08, Tiger Liu(BJ-RD) wrote: >> Dear All: >> I have a question about MP Services Protocol. >> Does it support Hyper-threading technology? >> >> For example: >> A Quad-cores CPU(with HT feature support), actually it is equal to 8 logical cores. >> Take assumption 8 logical cores are all healthy and being enabled. >> >> So: >> >> 1. Will EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors()return total 8 logical processor cores? >> >> 2. Will EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() make all 8 logical cores do some tasks simultaneously? > > My understanding is "yes", to both questions. Most of the MP stuff deals > with "logical processors". > > > BTW, if you check the EFI_MP_SERVICES_GET_PROCESSOR_INFO prototype, it > outputs EFI_PROCESSOR_INFORMATION. The latter has the following fields: > > EFI_CPU_PHYSICAL_LOCATION Location; > EXTENDED_PROCESSOR_INFORMATION ExtendedInformation; > > The former gives you a package/core/thread identification for a > particular processor number. The latter (optionally) provides a 6-level > description (package / module / tile / die / core / thread). In each > information structure, "logical thread" is the finest granularity > information. > > hth > Laszlo > > > > > > > > > > > >