On Fri, Jun 17, 2011 at 4:28 AM, Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote:
>
> Something like so? Compiles and runs the benchmark in question.
Yup.
Except I really think that test for a NULL anon_vma should go away.
If an avc entry has a NULL anon_vma, something is seriously wrong. The
comment about anon_vma_fork failure is definitely just bogus: the
anon_vma is allocated before the avc entry, so there's no way a avc
can have a NULL anon_vma from there.
But yes, your patch is cleaner than the one I was playing around with
(your "remove if not list empty" is prettier than what I was toying
with - having a separate flag in the avc)
Tim, can you test Peter's (second - the cleaned up one) patch on top
of mine, and see if that helps things further?
The only thing I don't love about the batching is that we now do hold
the lock over some situations where we _could_ have allowed
concurrency (notably some avc allocations), but I think it's a good
trade-off. And walking the list twice at unlink_anon_vmas() should be
basically free.
Linus
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>