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-rw-r--r--mm/rmap.c39
1 files changed, 23 insertions, 16 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index b3e381919835..2df75a119c83 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -22,9 +22,10 @@
*
* inode->i_mutex (while writing or truncating, not reading or faulting)
* mm->mmap_sem
- * page->flags PG_locked (lock_page)
+ * page->flags PG_locked (lock_page) * (see huegtlbfs below)
* hugetlbfs_i_mmap_rwsem_key (in huge_pmd_share)
* mapping->i_mmap_rwsem
+ * hugetlb_fault_mutex (hugetlbfs specific page fault mutex)
* anon_vma->rwsem
* mm->page_table_lock or pte_lock
* pgdat->lru_lock (in mark_page_accessed, isolate_lru_page)
@@ -43,6 +44,11 @@
* anon_vma->rwsem,mapping->i_mutex (memory_failure, collect_procs_anon)
* ->tasklist_lock
* pte map lock
+ *
+ * * hugetlbfs PageHuge() pages take locks in this order:
+ * mapping->i_mmap_rwsem
+ * hugetlb_fault_mutex (hugetlbfs specific page fault mutex)
+ * page->flags PG_locked (lock_page)
*/
#include <linux/mm.h>
@@ -1178,6 +1184,9 @@ void page_add_new_anon_rmap(struct page *page,
VM_BUG_ON_PAGE(!PageTransHuge(page), page);
/* increment count (starts at -1) */
atomic_set(compound_mapcount_ptr(page), 0);
+ if (hpage_pincount_available(page))
+ atomic_set(compound_pincount_ptr(page), 0);
+
__inc_node_page_state(page, NR_ANON_THPS);
} else {
/* Anon THP always mapped first with PMD */
@@ -1406,6 +1415,9 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
/*
* If sharing is possible, start and end will be adjusted
* accordingly.
+ *
+ * If called for a huge page, caller must hold i_mmap_rwsem
+ * in write mode as it is possible to call huge_pmd_unshare.
*/
adjust_range_if_pmd_sharing_possible(vma, &range.start,
&range.end);
@@ -1453,6 +1465,12 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
address = pvmw.address;
if (PageHuge(page)) {
+ /*
+ * To call huge_pmd_unshare, i_mmap_rwsem must be
+ * held in write mode. Caller needs to explicitly
+ * do this outside rmap routines.
+ */
+ VM_BUG_ON(!(flags & TTU_RMAP_LOCKED));
if (huge_pmd_unshare(mm, &address, pvmw.pte)) {
/*
* huge_pmd_unshare unmapped an entire PMD
@@ -1696,23 +1714,9 @@ discard:
return ret;
}
-bool is_vma_temporary_stack(struct vm_area_struct *vma)
-{
- int maybe_stack = vma->vm_flags & (VM_GROWSDOWN | VM_GROWSUP);
-
- if (!maybe_stack)
- return false;
-
- if ((vma->vm_flags & VM_STACK_INCOMPLETE_SETUP) ==
- VM_STACK_INCOMPLETE_SETUP)
- return true;
-
- return false;
-}
-
static bool invalid_migration_vma(struct vm_area_struct *vma, void *arg)
{
- return is_vma_temporary_stack(vma);
+ return vma_is_temporary_stack(vma);
}
static int page_mapcount_is_zero(struct page *page)
@@ -1974,6 +1978,9 @@ void hugepage_add_new_anon_rmap(struct page *page,
{
BUG_ON(address < vma->vm_start || address >= vma->vm_end);
atomic_set(compound_mapcount_ptr(page), 0);
+ if (hpage_pincount_available(page))
+ atomic_set(compound_pincount_ptr(page), 0);
+
__page_set_anon_rmap(page, vma, address, 1);
}
#endif /* CONFIG_HUGETLB_PAGE */