From mboxrd@z Thu Jan 1 00:00:00 1970 From: Srivatsa Vaddagiri Date: Tue, 21 Jun 2011 06:56:07 +0000 Subject: Re: [PATCH 00/10] Enhance /dev/mem to allow read/write of Message-Id: <20110621065542.GA13432@linux.vnet.ibm.com> List-Id: References: <201106171038.25988.ptesarik@suse.cz> <20110617093032.GA19235@elte.hu> <4DFE7FF9.9070406@gmail.com> <4DFE89E0.5020509@zytor.com> <20110620074124.GB24716@elte.hu> <4DFF6E58.8090306@zytor.com> In-Reply-To: <4DFF6E58.8090306@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org On Mon, Jun 20, 2011 at 08:59:20AM -0700, H. Peter Anvin wrote: > We should either fix /dev/mem to work according to its specification or > rip it out. The issue with test drivers is not spurious... I ran into > this one myself a few weeks ago while trying to do a memory test (by > limiting the amount of memory available to the kernel). This is > something that is typically done on factory floors, and it would be nice > to be able to get those environments over to using Linux. We came across a similar request from our manufacturing folks. They have a memory stress tool that needs to test how much bandwidth is possible between various cpus and memory modules. Essentially they want the tool to run on some chosen CPU and want it to drive traffic to some chosen memory module. /dev/mem would be handy for such test programs .. - vatsa From mboxrd@z Thu Jan 1 00:00:00 1970 From: vatsa@linux.vnet.ibm.com (Srivatsa Vaddagiri) Date: Tue, 21 Jun 2011 12:25:42 +0530 Subject: [PATCH 00/10] Enhance /dev/mem to allow read/write of arbitrary physical addresses In-Reply-To: <4DFF6E58.8090306@zytor.com> References: <201106171038.25988.ptesarik@suse.cz> <20110617093032.GA19235@elte.hu> <4DFE7FF9.9070406@gmail.com> <4DFE89E0.5020509@zytor.com> <20110620074124.GB24716@elte.hu> <4DFF6E58.8090306@zytor.com> Message-ID: <20110621065542.GA13432@linux.vnet.ibm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Jun 20, 2011 at 08:59:20AM -0700, H. Peter Anvin wrote: > We should either fix /dev/mem to work according to its specification or > rip it out. The issue with test drivers is not spurious... I ran into > this one myself a few weeks ago while trying to do a memory test (by > limiting the amount of memory available to the kernel). This is > something that is typically done on factory floors, and it would be nice > to be able to get those environments over to using Linux. We came across a similar request from our manufacturing folks. They have a memory stress tool that needs to test how much bandwidth is possible between various cpus and memory modules. Essentially they want the tool to run on some chosen CPU and want it to drive traffic to some chosen memory module. /dev/mem would be handy for such test programs .. - vatsa From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752136Ab1FUGzy (ORCPT ); Tue, 21 Jun 2011 02:55:54 -0400 Received: from e6.ny.us.ibm.com ([32.97.182.146]:45242 "EHLO e6.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751137Ab1FUGzv (ORCPT ); Tue, 21 Jun 2011 02:55:51 -0400 Date: Tue, 21 Jun 2011 12:25:42 +0530 From: Srivatsa Vaddagiri To: "H. Peter Anvin" Cc: Ingo Molnar , Ryan Mallon , Petr Tesarik , Andrew Morton , Fenghua Yu , Ingo Molnar , Paul Mundt , Russell King , Thomas Gleixner , Tony Luck , x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, linux-kernel@vger.kernel.org, Arjan van de Ven , Dave Jones , Linus Torvalds Subject: Re: [PATCH 00/10] Enhance /dev/mem to allow read/write of arbitrary physical addresses Message-ID: <20110621065542.GA13432@linux.vnet.ibm.com> Reply-To: vatsa@linux.vnet.ibm.com References: <201106171038.25988.ptesarik@suse.cz> <20110617093032.GA19235@elte.hu> <4DFE7FF9.9070406@gmail.com> <4DFE89E0.5020509@zytor.com> <20110620074124.GB24716@elte.hu> <4DFF6E58.8090306@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4DFF6E58.8090306@zytor.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 20, 2011 at 08:59:20AM -0700, H. Peter Anvin wrote: > We should either fix /dev/mem to work according to its specification or > rip it out. The issue with test drivers is not spurious... I ran into > this one myself a few weeks ago while trying to do a memory test (by > limiting the amount of memory available to the kernel). This is > something that is typically done on factory floors, and it would be nice > to be able to get those environments over to using Linux. We came across a similar request from our manufacturing folks. They have a memory stress tool that needs to test how much bandwidth is possible between various cpus and memory modules. Essentially they want the tool to run on some chosen CPU and want it to drive traffic to some chosen memory module. /dev/mem would be handy for such test programs .. - vatsa