Re: Machine's high load when HIGHMEM is enabled

[Andrew Morton]

vasya vasyaev wrote:
> 
> Hello,
> 
> First of all - thanks to these people, who responded
> to my question.
> 
> I have some news...
> 
> I've tried kernels:
> 2.4.19 - the same result
> 2.5.44 - the same result
> 2.5.45 - the same result
> 
> If I take 1 Gb of memory away, then computer works
> much better, faster (something like without enabled
> HIGHMEM at all).
> The same effect takes place if I say mem=1024M while
> physically box has 2Gb of RAM - everything is fine!
> But if I start HIGHMEM enabled kernel on this box (2Gb
> RAM), then it works too slowly...
> 

Please ensure that the mtrr driver is enabled in kernel config,
boot with mem=2G and send the output of `cat /proc/mtrr'.

Also, `dmesg | head -120' would be interesting.