From 30dad30922ccc733cfdbfe232090cf674dc374dc Mon Sep 17 00:00:00 2001 From: Naoya Horiguchi Date: Wed, 12 Jun 2013 14:05:04 -0700 Subject: mm: migration: add migrate_entry_wait_huge() When we have a page fault for the address which is backed by a hugepage under migration, the kernel can't wait correctly and do busy looping on hugepage fault until the migration finishes. As a result, users who try to kick hugepage migration (via soft offlining, for example) occasionally experience long delay or soft lockup. This is because pte_offset_map_lock() can't get a correct migration entry or a correct page table lock for hugepage. This patch introduces migration_entry_wait_huge() to solve this. Signed-off-by: Naoya Horiguchi Reviewed-by: Rik van Riel Reviewed-by: Wanpeng Li Reviewed-by: Michal Hocko Cc: Mel Gorman Cc: Andi Kleen Cc: KOSAKI Motohiro Cc: [2.6.35+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/hugetlb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/hugetlb.c') diff --git a/mm/hugetlb.c b/mm/hugetlb.c index f8feeeca6686..e2bfbf73a551 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2839,7 +2839,7 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, if (ptep) { entry = huge_ptep_get(ptep); if (unlikely(is_hugetlb_entry_migration(entry))) { - migration_entry_wait(mm, (pmd_t *)ptep, address); + migration_entry_wait_huge(mm, ptep); return 0; } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) return VM_FAULT_HWPOISON_LARGE | -- cgit v1.2.1