The patch titled
Subject: mm/hugetlb: enable arch specific huge page size support for migration
has been added to the -mm tree. Its filename is
mm-hugetlb-enable-arch-specific-huge-page-size-support-for-migration.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-hugetlb-enable-arch-specific-huge-page-size-support-for-migration.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-hugetlb-enable-arch-specific-huge-page-size-support-for-migration.patch
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------------------------------------------------------
From: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Subject: 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@xxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Reviewed-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Reviewed-by: Steve Capper <steve.capper@xxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/include/linux/hugetlb.h~mm-hugetlb-enable-arch-specific-huge-page-size-support-for-migration
+++ a/include/linux/hugetlb.h
@@ -493,18 +493,29 @@ static inline pgoff_t basepage_index(str
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);
}
/*
_
Patches currently in -mm which might be from anshuman.khandual@xxxxxxx are
mm-replace-all-open-encodings-for-numa_no_node.patch
mm-hugetlb-distinguish-between-migratability-and-movability.patch
mm-hugetlb-enable-pud-level-huge-page-migration.patch
mm-hugetlb-enable-arch-specific-huge-page-size-support-for-migration.patch
arm64-mm-enable-hugetlb-migration.patch
arm64-mm-enable-hugetlb-migration-for-contiguous-bit-hugetlb-pages.patch
