Re: mmap'ed memory cacheable or uncheable

[Jun Sun <jsun@mvista.com>]

On Fri, Jul 25, 2003 at 03:52:33PM -0700, Teresa Tao wrote:
> How about if I specify the following flags in my mmap routine just like what 
> the pgprot_noncached micro did.
>       pgprot_val(vma->vm_page_prot) &= ~_CACHE_MASK;
>       pgprot_val(vma->vm_page_prot) |= _CACHE_UNCACHED;
> 
> Will this have kernel make the mmap'd memory non-cacheable? Or is there a 
> mmap non-cacheable patch?
>

I think this might work.  Did you try it?  The performance will be bad
though as mmap() is used widely by userland.

Jun