From 33a938774fdb9933e9c77504b035f4f87c0859df Mon Sep 17 00:00:00 2001 From: Andrea Arcangeli Date: Tue, 25 Jan 2011 15:07:25 -0800 Subject: [PATCH] mm: compaction: don't depend on HUGETLB_PAGE Commit 5d6892407 ("thp: select CONFIG_COMPACTION if TRANSPARENT_HUGEPAGE enabled") causes this warning during the configuration process: warning: (TRANSPARENT_HUGEPAGE) selects COMPACTION which has unmet direct dependencies (EXPERIMENTAL && HUGETLB_PAGE && MMU) COMPACTION doesn't depend on HUGETLB_PAGE, it doesn't depend on THP either, it is also useful for regular alloc_pages(order > 0) including the very kernel stack during fork (THREAD_ORDER = 1). It's always better to enable COMPACTION. The warning should be an error because we would end up with MIGRATION not selected, and COMPACTION wouldn't work without migration (despite it seems to build with an inline migrate_pages returning -ENOSYS). I'd also like to remove EXPERIMENTAL: compaction has been in the kernel for some releases (for full safety the default remains disabled which I think is enough). Signed-off-by: Andrea Arcangeli Reported-by: Luca Tettamanti Tested-by: Luca Tettamanti Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/Kconfig b/mm/Kconfig index 3ad483bdf505..e9c0c61f2ddd 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -179,7 +179,7 @@ config SPLIT_PTLOCK_CPUS config COMPACTION bool "Allow for memory compaction" select MIGRATION - depends on EXPERIMENTAL && HUGETLB_PAGE && MMU + depends on MMU help Allows the compaction of memory for the allocation of huge pages.