From: David Jander <david.jander@protonic.nl>
To: "Gunnar Von Boehn" <gunnar@genesi-usa.com>
Cc: munroesj@us.ibm.com, John Rigby <jrigby@freescale.com>,
linuxppc-dev@ozlabs.org, Paul Mackerras <paulus@samba.org>,
prodyut hazarika <prodyuth@gmail.com>
Subject: Re: Efficient memcpy()/memmove() for G2/G3 cores...
Date: Thu, 4 Sep 2008 18:32:29 +0200 [thread overview]
Message-ID: <200809041832.29931.david.jander@protonic.nl> (raw)
In-Reply-To: <b989d750809040801x50019cf9j9741219348c9b5f7@mail.gmail.com>
On Thursday 04 September 2008 17:01:21 Gunnar Von Boehn wrote:
>[...]
> Regarding the 5121.
> David, you did create a very special memcopy for the 5121e CPU.
> Your test showed us that the normal glibc memcopy is about 10 times
> slower than expected on the 5121.
>
> I really wonder why this is the case.
> I would have expected the 5121 to perform just like the 5200B.
> What we saw is that switching from READ to WRITE and back is very
> costly on 5121.
>
> There seems to be a huge difference between the 5200 and its successor the
> 5121. Is this performance difference caused by the CPU or by the board
> /memory?
I have some new insight now, and I will look more closely at the working of
the DRAM controller... there has to be something wrong somewhere, an I am
going to find it... whether it is some strange bug in my u-boot code
(initializing the DRAM controller and prio-manager for example) or a
silicon-errata (John?)
Thanks a lot for your help so far.
--
David Jander
next prev parent reply other threads:[~2008-09-04 16:32 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-08-25 9:31 Efficient memcpy()/memmove() for G2/G3 cores David Jander
2008-08-25 11:00 ` Matt Sealey
2008-08-25 13:06 ` David Jander
2008-08-25 22:28 ` Benjamin Herrenschmidt
2008-08-27 21:04 ` Steven Munroe
2008-08-29 11:48 ` David Jander
2008-08-29 12:21 ` Joakim Tjernlund
2008-09-01 7:23 ` David Jander
2008-09-01 9:36 ` Joakim Tjernlund
2008-09-02 13:12 ` David Jander
2008-09-03 6:43 ` Joakim Tjernlund
2008-09-03 20:33 ` prodyut hazarika
2008-09-04 2:04 ` Paul Mackerras
2008-09-04 12:05 ` David Jander
2008-09-04 12:19 ` Josh Boyer
2008-09-04 12:59 ` David Jander
2008-09-04 14:31 ` Steven Munroe
2008-09-04 14:45 ` Gunnar Von Boehn
2008-09-04 15:14 ` Gunnar Von Boehn
2008-09-04 16:25 ` David Jander
2008-09-04 15:01 ` Gunnar Von Boehn
2008-09-04 16:32 ` David Jander [this message]
2008-09-04 18:14 ` prodyut hazarika
2008-08-29 20:34 ` Steven Munroe
2008-09-01 8:29 ` David Jander
2008-08-31 8:28 ` Benjamin Herrenschmidt
2008-09-01 6:42 ` David Jander
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