From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754630Ab0EIQtn (ORCPT ); Sun, 9 May 2010 12:49:43 -0400 Received: from mail.tmr.com ([64.65.253.246]:38907 "EHLO posidon.tmr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754572Ab0EIQtk (ORCPT ); Sun, 9 May 2010 12:49:40 -0400 Message-ID: <4BE6E79B.5080608@tmr.com> Date: Sun, 09 May 2010 12:49:31 -0400 From: Bill Davidsen User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.10) Gecko/20100504 NOT Firefox/3.5.3 SeaMonkey/2.0.5 MIME-Version: 1.0 To: LKML CC: microblaze-uclinux@itee.uq.edu.au Subject: Re: Microblaze - The fist year References: <4BC461AD.6090504@monstr.eu> <4BC46DC6.5050309@lumino.de> <4BC4713F.6030702@monstr.eu> <4BC57478.3080902@lumino.de> In-Reply-To: <4BC57478.3080902@lumino.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Michael Schnell wrote: > On 04/13/2010 03:27 PM, Michal Simek wrote: >> >> yes, futex is there. You can check it in >> arch/microblaze/include/asm/futex.h > Great ! I'll check how this is done. >> >>> Does Microblaze MMU Linux support SMP ? >> >> It is possible to connect several MicroBlazes but the problem is >> missing cache coherency modul. I hope that Xilinx will release any >> version which will support it. >> We haven't done any significant work to support it but it is expected >> solution which will happen. > > Besides cache coherency, another problem might be doing FUTEX. here (I > suppose) SMP safe atomic user space operations are necessary. many > simple RISK (load/store-) CPUs don't provide these (new ARMs provide > "load-locked / store-conditional" on that behalf as an extension to the > load/store paradigm. I suppose these can be done in an SMP-safe way, > supposedly using the hardware that provides cache coherency). > I wonder if you could make this work with some variant of NUMA configuration. I don't predict anything about being practical even if it works, just a thought. -- Bill Davidsen "We have more to fear from the bungling of the incompetent than from the machinations of the wicked." - from Slashdot