Memory allocation from ZONE_HIGHMEM ???

[Pintu Agarwal <pintu_agarwal@xxxxxxxxx>]

Hi,

 

I have a question regarding kernel memory allocation(using kmalloc) from ZONE_HIGHMEM zone.

 

I have a custom linux kernel2.6.36 running on linux mobile (arm cortexA9)

I have two zones on my system as shown by buddyinfo.

=====================================================

/opt/home/root # cat /proc/buddyinfo
Node 0, zone   Normal      2     32     22     14     12      4     12      3      0      1     23
Node 0, zone  HighMem    529    243    114     43     25     23     19     19     16     14     27

=====================================================

 

When I do memory allocation using kmalloc, the pages are allocated from Normal zone.

My allocation size is for order-10 pages = 23 * 1024 * PAGE_SIZE = 80MB

If I use more than that my allocation will fail which is obvious.

 

But I want to specifically allocate pages from ZONE_HIGHMEM instead of Normal zone.

How to explicitly do that in kernel?

 

If somebody have tried this please let me know.

 

 

 

Thanks, Regards,

Pintu