Messages in this thread | | | Date | Fri, 9 Nov 2012 15:42:57 +0100 | From | Andrea Arcangeli <> | Subject | Re: [RFC PATCH 00/19] Foundation for automatic NUMA balancing |
| |
Hi Mel,
On Tue, Nov 06, 2012 at 09:14:36AM +0000, Mel Gorman wrote: > This series addresses part of the integration and sharing problem by > implementing a foundation that either the policy for schednuma or autonuma > can be rebased on. The actual policy it implements is a very stupid > greedy policy called "Migrate On Reference Of pte_numa Node (MORON)". > While stupid, it can be faster than the vanilla kernel and the expectation > is that any clever policy should be able to beat MORON. The advantage is > that it still defines how the policy needs to hook into the core code -- > scheduler and mempolicy mostly so many optimisations (s uch as native THP > migration) can be shared between different policy implementations.
I haven't had much time to look into it yet, because I've been attending KVM Forum the last few days, but this foundation looks ok with me as a starting base and I ack it for merging it upstream. I'll try to rebase on top of this and send you some patches.
> Patch 14 adds a MPOL_MF_LAZY mempolicy that an interested application can use. > On the next reference the memory should be migrated to the node that > references the memory.
This approach of starting with a stripped down foundation won't allow for easy backportability anyway, so merging the userland API at the first step shouldn't provide any benefit for the work that is ahead of us. I would leave this for later and not part of the foundation.
All we need is a failsafe runtime and boot time turn off knob, just in case.
Thanks, Andrea
| |