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From: Sanjay Patel <sanjay3000@yahoo.com>
To: Arnd Bergmann <arnd@arndb.de>, Gunnar von Boehn <VONBOEHN@de.ibm.com>
Cc: Mark Nelson <markn@au1.ibm.com>,
	linuxppc-dev@ozlabs.org, Michael Ellerman <ellerman@au1.ibm.com>,
	cbe-oss-dev@ozlabs.org
Subject: Re: [RFC 1/3] powerpc: __copy_tofrom_user tweaked for Cell
Date: Thu, 19 Jun 2008 09:13:09 -0700 (PDT)	[thread overview]
Message-ID: <973448.15152.qm@web33101.mail.mud.yahoo.com> (raw)
In-Reply-To: <OF3C6636F6.52E3D242-ONC125746D.005214B0-C125746D.0053FABE@de.ibm.com>




--- On Thu, 6/19/08, Gunnar von Boehn <VONBOEHN@de.ibm.com> wrote:

> You are right the main copy2user requires that the SRC is
> cacheable.
> IMHO because of the exception on load, the routine should
> fallback to the
> byte copy loop.
> 
> Arnd, could you verify that it works on localstore?

Since the main loops use 'dcbz', the destination must also be cacheable. IIRC, if the destination is write-through or cache-inhibited, the 'dcbz' will cause an alignment exception. I suppose it would still function correctly via the handler, but horribly slowly.

--Sanjay




      

  reply	other threads:[~2008-06-19 16:19 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-06-19  7:53 [RFC 1/3] powerpc: __copy_tofrom_user tweaked for Cell Mark Nelson
2008-06-19 14:43 ` Arnd Bergmann
2008-06-19 15:17   ` Gunnar von Boehn
2008-06-19 16:13     ` Sanjay Patel [this message]
2008-06-20 11:36       ` Gunnar von Boehn
2008-06-20 17:46         ` Sanjay Patel
2008-06-20 23:20           ` Benjamin Herrenschmidt
2008-06-20 23:44             ` Sanjay Patel
2008-06-23  8:30           ` Gunnar von Boehn
2008-06-23 12:07             ` Geert Uytterhoeven
2008-06-23 23:49             ` Paul Mackerras
2008-06-27 13:30               ` Gunnar von Boehn
2008-06-20  1:13     ` [Cbe-oss-dev] " Paul Mackerras
2008-06-20 16:47       ` Gunnar von Boehn
2008-06-21  2:00       ` Arnd Bergmann
2008-06-21  4:30         ` Paul Mackerras
2008-06-21  4:49           ` David Miller
2008-06-21 21:06           ` Arnd Bergmann
2008-06-20  1:55   ` Mark Nelson

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