This is the ver.4 of hugepage migration fix patchset. Major changes from ver.3 are: - to drop locking from follow_huge_pud() and follow_huge_addr() in patch 2, which was buggy and is not necessary now because they don't support FOLL_GET, - follow_huge_pmd(FOLL_GET) can pin and return tail pages, - and I fixed bugs accidentally introduced in patch 3 and 5. Others are code improvements and comment/description fixes. Two related topics (not included in this series but to be discussed/done) - follow_huge_pmd() explicitly uses pmd_lockptr() instead of huge_pte_lock(). This point shed light on the subtlety in huge_page_size == PMD_HUGE check in huge_pte_lockptr(). This seems to make no runtime problem now, but might look fragile for example when pmd is folded (where PUD_SIZE == PMD_SIZE) or when hugepage in your architecture is not bound by page table (where hugepage size happens to equal with PMD_SIZE.) - code around is_hugetlb_entry_migration() and is_hugetlb_entry_hwpoisoned() is not beautiful or optimized. Cleanup is necessary. This patchset is based on mmotm-2014-09-09-14-42 and shows no regression in libhugetlbfs test. Tree: git@xxxxxxxxxx:Naoya-Horiguchi/linux.git Branch: mmotm-2014-09-09-14-42/fix_follow_huge_pmd.v4 v2: http://thread.gmane.org/gmane.linux.kernel/1761065 v3: http://thread.gmane.org/gmane.linux.kernel/1776585 --- Summary: Naoya Horiguchi (5): mm/hugetlb: reduce arch dependent code around follow_huge_* mm/hugetlb: take page table lock in follow_huge_pmd() mm/hugetlb: fix getting refcount 0 page in hugetlb_fault() mm/hugetlb: add migration/hwpoisoned entry check in hugetlb_change_protection mm/hugetlb: add migration entry check in __unmap_hugepage_range arch/arm/mm/hugetlbpage.c | 6 -- arch/arm64/mm/hugetlbpage.c | 6 -- arch/ia64/mm/hugetlbpage.c | 6 -- arch/metag/mm/hugetlbpage.c | 6 -- arch/mips/mm/hugetlbpage.c | 18 ------ arch/powerpc/mm/hugetlbpage.c | 8 +++ arch/s390/mm/hugetlbpage.c | 20 ------- arch/sh/mm/hugetlbpage.c | 12 ---- arch/sparc/mm/hugetlbpage.c | 12 ---- arch/tile/mm/hugetlbpage.c | 28 ---------- arch/x86/mm/hugetlbpage.c | 12 ---- include/linux/hugetlb.h | 8 +-- mm/gup.c | 25 ++------- mm/hugetlb.c | 124 ++++++++++++++++++++++++++++-------------- mm/migrate.c | 3 +- 15 files changed, 101 insertions(+), 193 deletions(-) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
