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authorAnshuman Khandual <anshuman.khandual@arm.com>2019-03-05 15:43:51 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-03-05 21:07:15 -0800
commite693de186414ae66f2a316ff9befcd2b7a6d07b6 (patch)
tree8e14f71dc4d6df2c19a1585e387b37274950a049 /include/linux
parentmm/hugetlb: enable PUD level huge page migration (diff)
downloadlinux-dev-e693de186414ae66f2a316ff9befcd2b7a6d07b6.tar.xz
linux-dev-e693de186414ae66f2a316ff9befcd2b7a6d07b6.zip
mm/hugetlb: enable arch specific huge page size support for migration
Architectures like arm64 have HugeTLB page sizes which are different than generic sizes at PMD, PUD, PGD level and implemented via contiguous bits. At present these special size HugeTLB pages cannot be identified through macros like (PMD|PUD|PGDIR)_SHIFT and hence chosen not be migrated. Enabling migration support for these special HugeTLB page sizes along with the generic ones (PMD|PUD|PGD) would require identifying all of them on a given platform. A platform specific hook can precisely enumerate all huge page sizes supported for migration. Instead of comparing against standard huge page orders let hugetlb_migration_support() function call a platform hook arch_hugetlb_migration_support(). Default definition for the platform hook maintains existing semantics which checks standard huge page order. But an architecture can choose to override the default and provide support for a comprehensive set of huge page sizes. Link: http://lkml.kernel.org/r/1545121450-1663-4-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Steve Capper <steve.capper@arm.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/hugetlb.h15
1 files changed, 13 insertions, 2 deletions
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 70bcd8973323..4cc3871b65fc 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -493,18 +493,29 @@ static inline pgoff_t basepage_index(struct page *page)
extern int dissolve_free_huge_page(struct page *page);
extern int dissolve_free_huge_pages(unsigned long start_pfn,
unsigned long end_pfn);
-static inline bool hugepage_migration_supported(struct hstate *h)
-{
+
#ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
+#ifndef arch_hugetlb_migration_supported
+static inline bool arch_hugetlb_migration_supported(struct hstate *h)
+{
if ((huge_page_shift(h) == PMD_SHIFT) ||
(huge_page_shift(h) == PUD_SHIFT) ||
(huge_page_shift(h) == PGDIR_SHIFT))
return true;
else
return false;
+}
+#endif
#else
+static inline bool arch_hugetlb_migration_supported(struct hstate *h)
+{
return false;
+}
#endif
+
+static inline bool hugepage_migration_supported(struct hstate *h)
+{
+ return arch_hugetlb_migration_supported(h);
}
/*