increase lowmem value for ppc

Ruksen INANIR rukseninanir at
Thu Jul 17 21:22:37 EST 2008

Is there any side effects of changing the address splitting? What should 
i change for 2G/2G splitting? should i shift the kernel start?

Marco Stornelli wrote:
> Marco Stornelli ha scritto:
>> Ruksen INANIR ha scritto:
>>> Is there a way to increase the lowmem value for ppc. The MAX_LOW_MEM 
>>> is defined as max 768 MB. But a value around 1.5 G works with no 
>>> problem. But when i try to increase this value to 1520 or more, 
>>> kernel complaints about no space for memory allocation when loading 
>>> kernel modules.
>>> I do not want to use HIGHMEM config. What is the max lowmem value 
>>> for a ppc system? What other setting are needed to use 1520 MB (or 
>>> more) as lowmem .
>>> The ppc card has 2G on board memory. 2.4.22 kernel is used.
>>> Thanks
>>> _______________________________________________
>>> Linuxppc-embedded mailing list
>>> Linuxppc-embedded at
>> With 32-bit arch you may not use more than 1GB to map the memory 
>> (minus some space for some kernel operation). The value of 768MB was 
>> not there by chance.
> Only an additional comment: I meant with the address splitting 3G/1G. 
> To map more than 1GB, you have to change the splitting 2G/2G for example.

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