[linuxsh-dev] Re: System reset while INIT processing

[Masahiro A. <m-...@aa...>]

On Fri, 13 Jul 2001 14:48:47 +0900
SUGIOKA Toshinobu <su...@it...> wrote:

> At 14:03 01/07/13 +0900, Masahiro Abe <m-...@aa...> wrote:
> 
> >I would like to ask you about this patch. Is this real fix, or (kind of)
> >hiding the problem caused by another source? Sorry if this sounds silly,
> >I still don't understand the fundamentals of MMU and cache.
> 
> 'copy_user_page/clear_user_page' creates temporal TLB entry to avoid cache alias issue on some situation.
> and uses temporal virtual address (in P3) instead of requested address (in U0).
> 
> This entry should be flashed before adding next temporal TLB entry on this virtual address,
> otherwise multiple TLB hit will occur.

Thank you for your detailed explanation. It will help me a lot to
understand the situation.

> that patch flashes before adding new temporal TLB entry, but it might better to flash immediately after
> copy/clear memory.

So this means that instead of calling __flush_tlb_page BEFORE
update_mmu_cache, we should call it AFTER copy_page? I'm gonna try that.

=================================
Masahiro ABE, A&D Co., Ltd. Japan