Re: [PATCH] powerpc/8xx: fix regression introduced by cache coherency rewrite
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: 2009-09-25 01:51:29
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: 2009-09-25 01:51:29
On Thu, 2009-09-24 at 18:35 -0700, Rex Feany wrote:
Then I can boot and get to a shell, but userspace is slow. 8 seconds to mount /proc (vs. less then a second using my old kernel)! Maybe this is an unrelated issue? I'm pretty clueless about the details, I'm sorry. PG_arch_1 is used to prevent a cache flush unless it is actually needed? Then why would changing the location of the tlbil_va() make a difference?
I think there's more finishyness to 8xx than we thought. IE. That tlbil_va might have more reasons to be there than what the comment seems to advertize. Can you try to move it even higher up ? IE. Unconditionally at the beginning of set_pte_filter ? Also, if that doesn't help, can you try putting one in set_access_flags_filter() just below ? (Beware that there's two different versions of both functions, only the first one is compiled/used on 8xx). It's going to be hard for me to get that "right" since I don't really know what's going on with the core here, but I suppose if we get it moving along with extra tlb invalidations, that should be "good enough" until somebody who really knows what's going on comes up with possibly a better fix. Cheers, Ben.