Hi Arnd,
I have no results for P5/P6, but I did some tests on JS21 aka PPC-970.
On PPC-970 the CELL memcpy is faster than the current Linux routine.
This becomes really visible when you really copy memory-to-memory and are
not only working in the 2ndlevelcache.
Kind regards
Gunnar von Boehn
Arnd Bergmann
<[EMAIL PROTECTED]>
To
19/06/2008 13:53 [email protected]
cc
Mark Nelson <[EMAIL PROTECTED]>,
[EMAIL PROTECTED], Gunnar von
Boehn/Germany/Contr/[EMAIL PROTECTED],
Michael Ellerman
<[EMAIL PROTECTED]>
Subject
Re: [RFC 0/3] powerpc: memory copy
routines tweaked for Cell
On Thursday 19 June 2008, Mark Nelson wrote:
> The plan is to use Michael Ellerman's code patching work so that at
runtime
> if we're running on a Cell machine the new routines are called but
otherwise
> the existing memory copy routines are used.
Have you tried running this code on other platforms to see if it
actually performs worse on any of them? I would guess that the
older code also doesn't work too well on Power 5 and Power 6, so the
cell optimized version could give us a significant advantage as well,
albeit less than another CPU specific version.
Arnd <><
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