increase lowmem value for ppc

Marco Stornelli marco.stornelli at
Thu Jul 17 21:21:48 EST 2008

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.

Marco Stornelli
Embedded Software Engineer
CoRiTeL - Consorzio di Ricerca sulle Telecomunicazioni

marco.stornelli at
+39 06 72582838

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