Re: 2.6.20 instability

[Paul M. <le...@li...>]

On Tue, Jan 30, 2007 at 09:18:54AM +0100, Manuel Lauss wrote:
> > On Mon, Jan 29, 2007 at 06:40:24PM +0900, Paul Mundt wrote:
> > > We switched the lazy dcache writeback model to PG_dcache_dirty, which
> > > results in measurably less flushing. Unfortunately it seems like there
> > > are still some explicit flushes required that aren't being handled.
> > > 
> > > My boards do not frequently exhibit this behaviour however, so it's slow
> > > debugging. If you want a quick fix, you can either revert to PG_mapped
> > > behaviour, or insert a dummy flush for the faulting page's dcache lines
> > > in update_mmu_cache().
> > 
> > With commit 0ca6a188.. ("Lazy dcache writeback optimizations") applied
> > it seems pretty stable. I'll let it run overnight and see where
> > it fails.
> 
> Compiled a few large packages overnight, and none failed.
> If there is still a chance, can the aforementioned patch go into
> final 2.6.20? Otherwise SH is almost unusable.
> 
My hesitation with this so far has been that some folks in the office
have hit troubles booting from CF with that applied, which I didn't see
on SATA when I was debugging it initially. I would prefer not to break
one set of boards in exchange for another, though it looks like it's
going to be 2.6.21 before I can sort out the kmap API rework for the page
colouring, which I was hoping would fix the remaining issues.

I'll have Linus pull it for 2.6.20 if there are enough people that are
experiencing troubles with Linus's current tree as it is.