On Thu, 2012-10-25 at 16:09 -0700, Linus Torvalds wrote:

On Thu, Oct 25, 2012 at 7:39 AM, Peter Zijlstra [off-list ref] wrote:

quoted

So I think the below should work, we hold the spinlock over both rb-tree
modification as sp free, this makes mpol_shared_policy_lookup() which
returns the policy with an incremented refcount work with just the
spinlock.

Comments?

Looks reasonable, if annoyingly complex for something that shouldn't
be important enough for this. Oh well.

I agree with that.. Its just that when doing numa placement one needs to
respect the pre-existing placement constraints. I've not seen a way
around this.

However, please check me on this: the need for this is only for
linux-next right now, correct? All the current users in my tree are ok
with just the mutex, no?

Yes, the need comes from the numa stuff and I'll stick this patch in
there.

I completely missed Mel's patch turning it into a mutex, but I guess
that's what -next is for :-).

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>