* Special vmas that are non-mergable, non-mlock()able.
* Note: mm/huge_memory.c VM_NO_THP depends on this definition.
*/
-#define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_PFNMAP)
+#define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_PFNMAP | VM_MIXEDMAP)
/*
* mapping from the currently active vm_flags protection bits (the
static inline struct page *compound_head(struct page *page)
{
- if (unlikely(PageTail(page)))
- return page->first_page;
+ if (unlikely(PageTail(page))) {
+ struct page *head = page->first_page;
+
+ /*
+ * page->first_page may be a dangling pointer to an old
+ * compound page, so recheck that it is still a tail
+ * page before returning.
+ */
+ smp_rmb();
+ if (likely(PageTail(page)))
+ return head;
+ }
return page;
}
#ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
static inline int page_cpupid_xchg_last(struct page *page, int cpupid)
{
- return xchg(&page->_last_cpupid, cpupid);
+ return xchg(&page->_last_cpupid, cpupid & LAST_CPUPID_MASK);
}
static inline int page_cpupid_last(struct page *page)
}
static inline void page_cpupid_reset_last(struct page *page)
{
- page->_last_cpupid = -1;
+ page->_last_cpupid = -1 & LAST_CPUPID_MASK;
}
#else
static inline int page_cpupid_last(struct page *page)