[PATCH 0/6] hugetlb: V6 constrain allocation/free based on task mempolicy

[Lee Schermerhorn <lee.schermerhorn@hp.com>]

PATCH 0/6 hugetlb: numa control of persistent huge pages alloc/free

Against:  2.6.31-rc7-mmotm-090827-1651

This is V6 of a series of patches to provide control over the location
of the allocation and freeing of persistent huge pages on a NUMA
platform.   Please consider V6 [patches 1-6] for merging into mmotm.

This series uses two mechanisms to constrain the nodes from which
persistent huge pages are allocated:  1) the task NUMA mempolicy of
the task modifying "nr_hugepages", based on a suggestion by Mel Gorman;
and 2) a subset of the hugepages hstate sysfs attributes have been
added [in V4] to each node system device under:

	/sys/devices/node/node[0-9]*/hugepages.

The per node attibutes allow direct assignment of a huge page
count on a specific node, regardless of the task's mempolicy or
cpuset constraints.

V5 addressed review comments -- changes described in patch descriptions.

V6 addresses more review comments, described in the patches.

Attached to V6, I'm sending a 3 patch series that implements an
enhancement suggested by David Rientjes:   the default huge page nodes
allowed mask will be the nodes with memory rather than all on-line nodes.
The "nodes with memory" state already tracks memory/node hot-plug.
Further, we will allocate per node hstate attributes only for nodes with
memory.  This requires that we register a memory on/off-line notifier
and [un]register the attributes on transitions to/from memoryless state.

Because of the interaction with memory hotplug, these 3 patches will
likely require more work and testing before merging.  The first six
patches do not depend on these 3 and, IMO, need not wait for them.