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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Tirumala Reddy Marri <tmarri@amcc.com>
Cc: Olof Johansson <olof@lixom.net>, linuxppc-dev@ozlabs.org
Subject: RE: Disabling L1 D-cache and side effects
Date: Wed, 01 Oct 2008 07:30:36 +1000	[thread overview]
Message-ID: <1222810236.9006.54.camel@pasglop> (raw)
In-Reply-To: <AC5E1C3367E37D44970B81A6ADD1DA2C06053428@SDCEXCHANGE01.ad.amcc.com>

On Tue, 2008-09-30 at 09:57 -0700, Tirumala Reddy Marri wrote:
> Ben,
>   Thanks for the response. I am wondering how user space would get
> affected by absence of L1 Dcache.

You didn't answer my question :-)

Well, as I said, things like lwarx/stwcx not working, dcbz taking
alignment exceptions, etc...

Ben.

> Thanks,
> Marri
> 
> -----Original Message-----
> From: Benjamin Herrenschmidt [mailto:benh@kernel.crashing.org] 
> Sent: Tuesday, September 30, 2008 12:16 AM
> To: Tirumala Reddy Marri
> Cc: Olof Johansson; linuxppc-dev@ozlabs.org
> Subject: RE: Disabling L1 D-cache and side effects
> 
> On Mon, 2008-09-29 at 14:38 -0700, Tirumala Reddy Marri wrote:
> > Could you please point me to the which does the Critical error 
> > (Machine
> > Check) recovery. BTW I am successful booting the Linux until rootfs is
> 
> > being mounted. It fails to mount the Linux saying that blocks are 
> > corrupted in file system. I had to modify lots of initial bring up 
> > code to disable D-cache and make sure all TLB's are cache inhibited. 
> > Ando also made sure none of the misc_32.S , entry_32.S and head.S 
> > makes any references to d-cache.
> 
> Why the heck are you doing that btw ? AFAIK, as Olof says, things like
> atomic operations will not work, dcbz neither etc... it's likely that
> even if you manage to plaster around all of this in the kernel, whatever
> userspace code you'll try to run in userspace will blow up too...
> 
> Cheers,
> Ben.

  reply	other threads:[~2008-09-30 21:30 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <9323BAFB78DE7C4183466AD03F73EA424D46071D@SDCEXCHANGE01.ad.amcc.com>
2008-09-29 17:05 ` Disabling L1 D-cache and side effects Tirumala Reddy Marri
2008-09-29 18:04   ` Olof Johansson
2008-09-29 21:00     ` Tirumala Reddy Marri
2008-09-29 21:14       ` Olof Johansson
2008-09-29 21:38         ` Tirumala Reddy Marri
2008-09-30  7:16           ` Benjamin Herrenschmidt
2008-09-30 16:57             ` Tirumala Reddy Marri
2008-09-30 21:30               ` Benjamin Herrenschmidt [this message]
2008-09-30 22:26                 ` Tirumala Reddy Marri
2008-09-30 22:56                   ` Benjamin Herrenschmidt
2008-10-01 18:07                     ` Tirumala Reddy Marri

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