2.4.26 and MPC885 context switching time

[Wolfgang Denk]

In message <187119B8-515D-4903-AAB5-05BF80215A4D at aimsys.nl> you wrote:
> 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...

I just ran lmbench on a MPC866 system (CPU at 132 MHz, bus at 66 MHz):

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
--------- ------------- ------ ------ ------ ------ ------ ------- -------
tqm8xx     Linux 2.4.25 5.4500   27.5   30.3   39.0   36.0    37.7    33.5


There is definitely something wrong with Peter's measurements.

Best regards,

Wolfgang Denk

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