Re: [PATCH 05/12] Allow CONFIG_MIGRATION to be set without CONFIG_NUMA or memory hot-remove
From: Mel Gorman <hidden>
Date: 2010-02-19 14:09:28
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On Fri, Feb 19, 2010 at 09:21:11AM +0900, KAMEZAWA Hiroyuki wrote:
On Thu, 18 Feb 2010 18:02:35 +0000 Mel Gorman [off-list ref] wrote:quoted
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. Signed-off-by: Mel Gorman <redacted> Reviewed-by: Christoph Lameter <redacted> Reviewed-by: Rik van Riel <redacted>Reviewed-by: KAMEZAWA Hiroyuki <redacted> But see below.quoted
--- mm/Kconfig | 20 ++++++++++++++++---- 1 files changed, 16 insertions(+), 4 deletions(-)diff --git a/mm/Kconfig b/mm/Kconfig index 17b8947..b1c2781 100644 --- a/mm/Kconfig +++ b/mm/Kconfig@@ -168,17 +168,29 @@ config SPLIT_PTLOCK_CPUS default "4" # +# support for memory compaction +config COMPACTION + bool "Allow for memory compaction" + def_bool y + select MIGRATION + depends on EXPERIMENTAL && HUGETLBFS + help + Allows the compaction of memory for the allocation of huge pages. +I think + depends on MMU
Agreed. Thanks
quoted
+# # support for page migration # config MIGRATION bool "Page migration" def_bool y - depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE + depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION 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 -- 1.6.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
-- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>