On Mon, 4 Dec 2006, Andrew Morton wrote: > > The multi zone approach does not work with NUMA. NUMA only supports a > > single zone for memory policy control etc. > > Wot? memory policies are a per-vma thing?
They only apply to "policy_zone" of a node. policy_zone can only take a single type of zone (has been like it forever). Multiple zones could become a nightmare with an exploding number of zones on zonelists. I.e. instead of 1k zones on a nodelist we now have 2k for two or even 4k if you want to have support for memory policies for 4 zones per node. We will then increase the search time through zonelists and have to manage all the memory in the different zones. Balancing is going to be difficult. > I suspect you'll have to live with that. I've yet to see a vaguely sane > proposal to otherwise prevent unreclaimable, unmoveable kernel allocations > from landing in a hot-unpluggable physical memory region. Mel's approach already mananges memory in a chunks of MAX_ORDER. It is easy to just restrict the unmovable types of allocation to a section of the zone. Then we should be doing some work to cut down the number of unmovable allocations. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
