From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aravind Gopalakrishnan Subject: Re: [PATCH 0/1] speeding up cpu_up() Date: Mon, 4 May 2015 17:45:17 -0500 Message-ID: <5547F67D.2080307@amd.com> References: <1429404795-23260-1-git-send-email-lenb@kernel.org> <20150420071556.GB14315@gmail.com> <20150501224729.GN10239@pd.tnic> <55441D8C.2080509@amd.com> <55464925.5050600@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-bn1bon0116.outbound.protection.outlook.com ([157.56.111.116]:12288 "EHLO na01-bn1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750887AbbEDWpY (ORCPT ); Mon, 4 May 2015 18:45:24 -0400 In-Reply-To: <55464925.5050600@amd.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Borislav Petkov , Len Brown Cc: Ingo Molnar , X86 ML , Linux PM list , "linux-kernel@vger.kernel.org" , Thomas Gleixner , "H. Peter Anvin" On 5/3/2015 11:13 AM, Aravind Gopalakrishnan wrote: > > On 5/1/15 7:42 PM, Aravind Gopalakrishnan wrote: >> >> On 5/1/15 5:47 PM, Borislav Petkov wrote: >>> Aravind and I could probably test on a couple of AMD boxes to narrow >>> down. >>> >>> @Aravind, see here: >>> >>> https://lkml.kernel.org/r/87d69aab88c14d65ae1e7be55050d1b689b59b4b.1429402494.git.len.brown@intel.com >>> >>> >>> You could ask around whether a timeout is needed between the assertion >>> and deassertion of INIT done by the BSP when booting other cores. >> >> Sure, I'll ask around and try mdelay(0) on some systems as well. >> I can gather Fam15h, Fam16h but don't have K8's or older. >> >> Will let you know how it goes. > Update: > Fam15h Model00h-0fh, Fam15hModel60h and Fam16h Model 00h-0fh > processors boot fine with mdelay(0) and BSP brings up all secondary > cpus correctly. I don't have Fam15hModel30h system currently up, but > I'll try that too tomorrow. > > I am yet to get feedback from HW folks regarding this though. Tested a delay of 0 on Fam10h and Fam15h Model 30h-3fh and both work fine. Feedback from asking internally about this is that we should be OK to move to a no-delay default from K8 onwards. Thanks, -Aravind.