From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from esa4.hc3370-68.iphmx.com (esa4.hc3370-68.iphmx.com [216.71.155.144]) by mx.groups.io with SMTP id smtpd.web10.643.1580744055635986838 for ; Mon, 03 Feb 2020 07:34:15 -0800 Authentication-Results: mx.groups.io; dkim=pass header.i=@citrix.com header.s=securemail header.b=HaprvVsJ; spf=pass (domain: citrix.com, ip: 216.71.155.144, mailfrom: anthony.perard@citrix.com) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1580744055; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=blGdylUb6gNYA1zim7m75o7mBX8DZMRW1sgPM2KjldQ=; b=HaprvVsJwkq5gpALhgT3tRcEkvK21QBR0kckNs80bnricQ0mG8OwT75t ioHfDCuI1EAXC7jlGXSFG+cb+HuM4S4uva2cfvN0AEMzyq9lVchLT5bKL P2sYOOzeQBJ5B/qJq13ndNA37icYJ9rzU+7C3YJI5qp+psOQ9YPp032xZ k=; Authentication-Results: esa4.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none; spf=None smtp.pra=anthony.perard@citrix.com; spf=Pass smtp.mailfrom=anthony.perard@citrix.com; spf=None smtp.helo=postmaster@mail.citrix.com Received-SPF: None (esa4.hc3370-68.iphmx.com: no sender authenticity information available from domain of anthony.perard@citrix.com) identity=pra; client-ip=162.221.158.21; receiver=esa4.hc3370-68.iphmx.com; envelope-from="anthony.perard@citrix.com"; x-sender="anthony.perard@citrix.com"; x-conformance=sidf_compatible Received-SPF: Pass (esa4.hc3370-68.iphmx.com: domain of anthony.perard@citrix.com designates 162.221.158.21 as permitted sender) identity=mailfrom; client-ip=162.221.158.21; receiver=esa4.hc3370-68.iphmx.com; envelope-from="anthony.perard@citrix.com"; x-sender="anthony.perard@citrix.com"; x-conformance=sidf_compatible; x-record-type="v=spf1"; x-record-text="v=spf1 ip4:209.167.231.154 ip4:178.63.86.133 ip4:195.66.111.40/30 ip4:85.115.9.32/28 ip4:199.102.83.4 ip4:192.28.146.160 ip4:192.28.146.107 ip4:216.52.6.88 ip4:216.52.6.188 ip4:162.221.158.21 ip4:162.221.156.83 ip4:168.245.78.127 ~all" Received-SPF: None (esa4.hc3370-68.iphmx.com: no sender authenticity information available from domain of postmaster@mail.citrix.com) identity=helo; client-ip=162.221.158.21; receiver=esa4.hc3370-68.iphmx.com; envelope-from="anthony.perard@citrix.com"; x-sender="postmaster@mail.citrix.com"; x-conformance=sidf_compatible IronPort-SDR: 5KIbqJzYQazA99XwCH+6FArQml8qiSGariUVecq0JM3VF3n1QatCP/jbH0W5CuNIVQ+yeepoJf s5ZzcKrqEEMcD0gcFYejkVfZNJ2uWJBozmBEg3rH+SQF+K1a6c/bldbttHFDAMk5E0stGbm3M6 CevbUy+fnukbx7MudO+ffb48CnGlmqBoXnoSUHVVI5vcHvDzpxziXIPaBF9KeXyxRdSNPDL/CL 1C+LbryJv6xZJBM17AhZ0d2+pEVV4PNtrYn1AjeBbhJaHINN4p/9eTzaOn9HmJAiJ6cqC8eeFM myY= X-SBRS: 2.7 X-MesageID: 12470525 X-Ironport-Server: esa4.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.70,398,1574139600"; d="scan'208";a="12470525" Date: Mon, 3 Feb 2020 15:34:07 +0000 From: "Anthony PERARD" To: "Gao, Liming" CC: Laszlo Ersek , "devel@edk2.groups.io" , "Kinney, Michael D" , "Ard Biesheuvel" , "xen-devel@lists.xenproject.org" , "Justen, Jordan L" , Julien Grall , "Feng, Bob C" Subject: Re: [PATCH 2/5] MdePkg: Allow PcdFSBClock to by Dynamic Message-ID: <20200203153407.GH2306@perard.uk.xensource.com> References: <20200129121235.1814563-1-anthony.perard@citrix.com> <20200129121235.1814563-3-anthony.perard@citrix.com> MIME-Version: 1.0 In-Reply-To: Return-Path: anthony.perard@citrix.com Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline On Mon, Feb 03, 2020 at 01:34:55AM +0000, Gao, Liming wrote: > Anthony: > This change is OK to me. But if this PCD is configured as Dynamic, its value will be got from PCD service. This operation will take some time and cause the inaccurate time delay. Have you measured its impact? No, I haven't. But I don't think it matter in a Xen guest, the APIC timer is emulated anyway, so reading from a register of the APIC is going to be slower than getting the value from the PCD services, I think. (Hopefully, I'm not too wrong.) But I'll give it at measuring the difference, it would be interesting to know. Thanks, -- Anthony PERARD