From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sfi-mx-1.v28.ch3.sourceforge.com ([172.29.28.121] helo=mx.sourceforge.net) by h25xhf1.ch3.sourceforge.com with esmtp (Exim 4.69) (envelope-from ) id 1MNo6E-0002Et-6F for ltp-list@lists.sourceforge.net; Mon, 06 Jul 2009 13:19:14 +0000 Received: from mail-fx0-f208.google.com ([209.85.220.208]) by 29vjzd1.ch3.sourceforge.com with esmtp (Exim 4.69) id 1MNo6B-0000cl-7Q for ltp-list@lists.sourceforge.net; Mon, 06 Jul 2009 13:19:14 +0000 Received: by fxm4 with SMTP id 4so2859038fxm.10 for ; Mon, 06 Jul 2009 06:19:09 -0700 (PDT) Message-ID: <4A51E8EA.1050009@petalogix.com> Date: Mon, 06 Jul 2009 14:07:06 +0200 From: Michal Simek MIME-Version: 1.0 References: <4A4DFB77.1080700@petalogix.com> <200907031702.52612.arnd@arndb.de> <4A519A70.50801@petalogix.com> <200907061005.36094.arnd@arndb.de> In-Reply-To: <200907061005.36094.arnd@arndb.de> Subject: Re: [LTP] mmap syscall problem Reply-To: michal.simek@petalogix.com List-Id: Linux Test Project General Discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ltp-list-bounces@lists.sourceforge.net To: Arnd Bergmann Cc: LTP , Linux Kernel list , Grant Likely , Andrew Morton , Ingo Molnar , John Williams Arnd Bergmann wrote: > On Monday 06 July 2009, Michal Simek wrote: > >>> Does this happen on microblaze-mmu or microblaze-nommu, or both? >>> The mmap code for the two is very different. >>> >>> >> For MMU code. >> > > Could this be a cache-aliasing problem? If your cache is 'virtually-indexed' > (most architectures are 'physically-indexed'), the kernel may have written > into different parts of the D-cache than what the user space is reading > from. If you have a write-through cache, that can explain why you only > see the stale data at the beginning of the page -- the cache controller > is still busy writing back the data when you start reading it from > DRAM through the cache alias. > I don't think so because we run that test on Microblaze without caches and test failed too. I think that this is sufficient test to tell that the problem is not relate with caches. Michal > If this is your problem, then you need to implement flush_dcache_page() > and other functions that maintain cache consistency. See > Documentation/cachetlb.txt and http://www.linuxjournal.com/article/7105 > > Arnd <>< > -- Michal Simek, Ing. (M.Eng) PetaLogix - Linux Solutions for a Reconfigurable World w: www.petalogix.com p: +61-7-30090663,+42-0-721842854 f: +61-7-30090663 ------------------------------------------------------------------------------ _______________________________________________ Ltp-list mailing list Ltp-list@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ltp-list