Date: Sun, 7 Mar 2010 21:12:23 +0100 From: Bernd Walter <ticso@cicely7.cicely.de> To: Maks Verver <maksverver@geocities.com> Cc: freebsd-arm@freebsd.org Subject: Re: Performance of SheevaPlug on 8-stable Message-ID: <20100307201222.GB11192@cicely7.cicely.de> In-Reply-To: <4B9404DE.70607@geocities.com> References: <4B92BD9D.6030709@geocities.com> <20100306211715.GK58319@cicely7.cicely.de> <20100306215153.GL58319@cicely7.cicely.de> <20100306.152603.716362616846278503.imp@bsdimp.com> <4B9303E4.3090500@geocities.com> <20100307070010.GO58319@cicely7.cicely.de> <4B9404DE.70607@geocities.com>
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On Sun, Mar 07, 2010 at 08:56:14PM +0100, Maks Verver wrote: > On 03/07/2010 08:00 AM, Bernd Walter wrote: > > That's probably just because of different CPUs. > > I see a similar output on all of my systems with ARM920T CPU and > > still there is something wrong. > > That's strange indeed. I'm not sure if our problems are at all related > (as in: caused by the same problem) as you seem to be using fairly > different hardware. That's true, but the symptoms I see are quite similar, although the OS version seem to have an influence on how high the performance loss actually is. This fact is especially puzzling, because I would have either expected similar results or calulated performance. > In my case the kernel (at boot up) doesn't seem to even think caches are > enabled, which gives me some hope that if they were, then they would > work. In your case the kernel claims to enable them but then they don't > work. Seems different to me. It is just different code printing the details for your CPU. Take a look into sys/arm/arm/identcpu.c. There is "if xxx IC disabled else IC enabled" printing - if you see neither it is not printing from this code at all. > > Your loop isn't doing any data access, so it's just saying something > > about ICACHE not working. > > True enough. > > > But maybe it is not ICACHE itself and the memory pages are just > > declared uncacheable? > > Another possibility. If anyone has suggestions on how to investigate > this, I'd love to hear it. Me too. -- B.Walter <bernd@bwct.de> http://www.bwct.de Modbus/TCP Ethernet I/O Baugruppen, ARM basierte FreeBSD Rechner uvm.
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