From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753400AbbJMW0f (ORCPT ); Tue, 13 Oct 2015 18:26:35 -0400 Received: from bh-25.webhostbox.net ([208.91.199.152]:48286 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751037AbbJMW0d (ORCPT ); Tue, 13 Oct 2015 18:26:33 -0400 Subject: Re: [PATCH 1/1] Bumps limit of maximum core ID from 32 to 128. To: "Odzioba, Lukasz" References: <1444650812-17398-1-git-send-email-lukasz.odzioba@intel.com> <20151013203134.GA28106@roeck-us.net> Cc: "Yu, Fenghua" , "jdelvare@suse.de" , "lm-sensors@lm-sensors.org" , "linux-kernel@vger.kernel.org" , Phil Pokorny From: Guenter Roeck Message-ID: <561D8514.2040503@roeck-us.net> Date: Tue, 13 Oct 2015 15:26:28 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated_sender: linux@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: authenticated_id: linux@roeck-us.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/13/2015 03:02 PM, Odzioba, Lukasz wrote: > On Tuesday, October 12, 2015 at 10:32 PM, Guenter Roeck wrote: >> Why 128 instead of a more reasonable 64 ? What is the required minimum >> for Xeon Phi ? > > It would be fine today, but it will be not enough in 2016 and we would like to > give GNU/Linux distributions some time to propagate this patch. > For Knights Corner which is already on the market we need 61. > For Knights Landing we need 72. Pardon my ignorance ... those are Xeon Phi processors, and support up to 244 threads (for Knights Corner). Programming datasheet isn't easily available, so I have to guess a bit. Following the processor numbering scheme of "ordinary" processors, the CPU ID can therefore be up to 244 (at least) already today, meaning the limit would have to be 256 (assuming that the processor does support per-core temperature sensors). On the other side, the public datasheet suggests that there are only three temperature sensors. What am I missing here ? Thanks, Guenter > For future generation it is not yet public information. > >> Also, please consider using the subject line commonly used in hwmon, >> or at least point to the driver you are changing. > > Right, I forgot this time, I'll send another patch just tell me whether 128 > is ok, or please select any other value greater or equal known minimum > that you think will be more appropriate. > > Thanks, > Lukas > > >