Hello Mulyadi,

On Tue, Jul 10, 2012 at 9:42 PM, Mulyadi Santosa
[off-list ref] wrote:

Hi..

On Tue, Jul 10, 2012 at 6:51 PM, Arun KS [off-list ref] wrote:

quoted

Hello Experts,

I have a requirement to change __log_buf memory(kernel printk buffer)
as non cacheable memory.
How can I change the page attributes for changing cache policy to non cacheable?

I just can give short clue. I think somehow you must find its PTE
entry...there, IIRC there is page attribute that can be changed to
make it uncacheable.

cross check the Intel processor manual for further clarification (if
it's indeed x86 arch)

__log_buf size is 512KB and PTE is mapped to a 1MB section. So if I
change the attribute for this 1MB section, lot of other stuffs(in this
1MB bss section) will also become non-cachable. Looks like it is not
possible unless my __log_buf is 1MB in size.
Or I need to create another section like .init, .data, .bss and create
4KB pages(with two levels of Page Tables) instead of 1M section.

My  arch is arm-v7

Thanks,
Arun

--
regards,

Mulyadi Santosa
Freelance Linux trainer and consultant

blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com