From e9e96b39f932a065e14f5d5bab0797ae261d03b5 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Mon, 24 May 2010 14:32:21 -0700 Subject: 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 Reviewed-by: Christoph Lameter Reviewed-by: Rik van Riel Reviewed-by: KAMEZAWA Hiroyuki Cc: Minchan Kim Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/Kconfig | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) (limited to 'mm/Kconfig') diff --git a/mm/Kconfig b/mm/Kconfig index 9c61158308dc..527136b22384 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -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 -- cgit v1.2.3