Re: [PATCH 3/6] 8xx: invalidate non present TLBs

On Fri, 2009-10-09 at 01:01 +0200, Joakim Tjernlund wrote:

Ok, that's my understanding too and I think we had the tlbie in

quoted

update_mmu_cache to do the trick, though the comment is misleading
making it think that the only reason it's there is for the dcbst
problem. At least that's my understanding. That was lost recently in

2.6

quoted

so I'll have to put it back properly.

So you don't think my invalidate "only !present pages" patch in
do_page_fault is enough?

It might well be the right solution, I was talking about the code as we
have upstream today.

I don't think we do the pre-load to avoid the second fault, but we
It won't get much faster than my current patch. Trapping all DTLB
Errors to C won't make it faster, only more correct should there be
a bug in the asm version. Actually there is one that has been there
all the time, guarded flag is not set by DTLB Error.

There's other areas of improvements I suggested that can make it faster
such as avoiding the whole kernel/user test in the TLB misses.

Removing the stuff in DataTLBError can potentially make normal page
faults faster too by avoiding going through a bunch of useless code
before going to do the real thing in C :-)

As I said, the case of ACCESSED or DIRTY updates are rare enough to not
warrant code in the main page fault hot path.

Cheers,
Ben.