Commit e9e96b39 authored May 24, 2010 by Mel Gorman Committed by Linus Torvalds May 25, 2010

mm: allow CONFIG_MIGRATION to be set without CONFIG_NUMA or memory hot-remove



CONFIG_MIGRATION currently depends on CONFIG_NUMA or on the architecture
being able to hot-remove memory.  The main users of page migration such as
sys_move_pages(), sys_migrate_pages() and cpuset process migration are
only beneficial on NUMA so it makes sense.

As memory compaction will operate within a zone and is useful on both NUMA
and non-NUMA systems, this patch allows CONFIG_MIGRATION to be set if the
user selects CONFIG_COMPACTION as an option.

[akpm@linux-foundation.org: Depend on CONFIG_HUGETLB_PAGE]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 3fe2011f

mm/Kconfig

+14 −3

Original line number	Diff line number	Diff line
		@@ -171,6 +171,15 @@ config SPLIT_PTLOCK_CPUS
		default "999999" if DEBUG_SPINLOCK \|\| DEBUG_LOCK_ALLOC
		default "4"

		#
		# support for memory compaction
		config COMPACTION
		bool "Allow for memory compaction"
		select MIGRATION
		depends on EXPERIMENTAL && HUGETLB_PAGE && MMU
		help
		Allows the compaction of memory for the allocation of huge pages.

		#
		# support for page migration
		#
		@@ -180,9 +189,11 @@ config MIGRATION
		depends on NUMA \|\| ARCH_ENABLE_MEMORY_HOTREMOVE
		help
		Allows the migration of the physical location of pages of processes
		while the virtual addresses are not changed. This is useful for
		example on NUMA systems to put pages nearer to the processors accessing
		the page.
		while the virtual addresses are not changed. This is useful in
		two situations. The first is on NUMA systems to put pages nearer
		to the processors accessing. The second is when allocating huge
		pages as migration can relocate pages to satisfy a huge page
		allocation instead of reclaiming.

		config PHYS_ADDR_T_64BIT
		def_bool 64BIT \|\| ARCH_PHYS_ADDR_T_64BIT

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