Re: race with page_referenced_one->ptep_test_and_clear_young andpagetable setup/pulldown

[Rik van Riel]

On Fri, 05 Oct 2007 12:40:05 -0700
Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote:

> Well, isn't the correct fix to make Xen take all the pagetable locks
> while pinning/unpinning?  Adding exception handling to
> test_and_clear_bit would solve this particular race, but are there
> others (either now or potentially)?  Seems fragile.

You're right, holding the pagetable lock(s) across pinning/unpinning
operations would avoid the problem too.

While we do not care about the accessed bit, there are similar operations
going on with the dirty bit - which is a lot more important :)

-- 
All Rights Reversed
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/