On Wed, 2013-08-21 at 09:30 -0700, Linus Torvalds wrote: > I will be reverting the whole soft-dirty mess. I thought the > bit-mapping games it played were already too complicated (the patch to > pgtable-2level.h in commit 41bb3476b361 just makes me want to barf and > came in very late, so I'm not positive about the whole soft-dirty mess > in the first place). I really am not at all inclined to want to play > games in this area any more. It's too damn late in the release window.
Anything that makes me try to scavenge a new PTE bits makes me scream :-) Dunno if I'll manage to support this on power. Also, it sort-of duplicates what KVM does for dirty tracking (for migration, framebuffer updates, etc...). I wonder if KVM could consider switching to this scheme, but then we end up with a user "break KVM" file in /proc since the user can clear the refs. I'd have been happier if the whole thing had essentially used a parallel set of dirty tracking bitmaps (hooked up with the VMAs maybe). Add the overhead there for as many "clients" as you want who will use the facility and leave the PTE mostly alone basically. (I suppose we still need to play PTE tricks to differenciate soft dirty RO vs. COW RO on anonymous memory ?) Cheers, Ben. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
