Re: [PATCH 1/2] mm,migration: Prevent rmap_walk_[anon|ksm] seeing the wrong VMA information

Linus Torvalds
2010-05-08T19:53:57Z

On Sat, 8 May 2010, Andrea Arcangeli wrote:
>
> There is no broken (as in kernel crashing) locking in my THP
> patches.

It's not about crashing. It's about being a totally unmaintainable mess,
with ad-hoc temporary allocations, and loops over an unknown number of
spinlocks.

That's _broken_. B. R. O. K. E. N.

And in all cases there are fixes that I've pointed out. If you can't see
that, then that's _your_ problem. If you (or others) want your code
merged, then it had better _fix_ the total disaster before merging. It's
that simple.

The "lock root" thing you complain should also be easily fixable, by
keeping the root lock a separate issue from walking the actual anon_vma
(ie walk the anon_vma, but lock the root). You still don't have to lock
the whole list.

Linus