2.4.26 and MPC885 context switching time

[Jaap-Jan Boor]

I did once ran lmbench on a proprietry 850 based board running at  
62/31 Mhz
using 1 16-bit dram:

Context switching - times in microseconds - smaller is better
-------------------------------------------------------------
Host                 OS 2p/0K 2p/16K 2p/64K 8p/16K 8p/64K 16p/16K 16p/ 
64K
                         ctxsw  ctxsw  ctxsw ctxsw  ctxsw   ctxsw    
ctxsw
--------- ------------- ----- ------ ------ ------ ------ -------  
-------
test    Linux 2.4.25- 259.2  234.2         302.6          304.7

This is ~ 3x faster then your 100Mhz 885...

Jaap-Jan

On 15-jun-2005, at 16:55, Schaefer-Hutter, Peter wrote:



> Hi all,
>
> i'm evaluating IPC on the MPC885ADS and discovered
> that the context switching times seem to be quite
> disappointing (up to 1ms). As we need to do a lot
> of IPC later on, i'm interested bringing the time
> down.
>
> Therefore i wonder, if there are any known problems
> with the MMU on 8xx and 2.4.2x which might explain
> that?
>
> Or is this the expected context switching time for
> CPU @ 100 MHz (RAM @ 50 MHz)? Suggestions for a
> benchmark program?
>
> Thanks!
>
>   Peter
> _______________________________________________
> Linuxppc-embedded mailing list
> Linuxppc-embedded at ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-embedded
>
>
>

____
J.G.J. Boor                       Anton Philipsweg 1
Software Engineer                 1223 KZ Hilversum
AimSys bv                         tel. +31 35 689 1941
Postbus 2194, 1200 CD Hilversum   jjboor at aimsys dot nl