Re: [linuxsh-dev] SH-4 cache performance improvement

[Philipp R. <pr...@pa...>]

On Sun, Dec 03, 2000 at 12:08:15AM +0900, SUGIOKA Toshinobu wrote:
> current __flush_page_to_ram invalidates data cache of the page,
> but I think write back is sufficient.  
> 
> I'm not sure whether this patch causes synonym problem.

flush_page_to_ram implies that the page is not going to be accessed using
the kernel mapping for a while, so a writeback should be sufficient in
practice.  Using ocbp ratehr than ocbwb should definitely be correct and
might be just as fast, have you tried it ?

> Is this approach correct ?

Looks fine to me;  unfortunately, several people (including me) still seem
to be seeing what looks like random corruption of kernel memory (which isn't
affected by inconsistent vipt caches), so keeping the paranoid versions of
the cache handling routines might be a good idea.