Commit d95c0337 authored by Mike Kravetz's avatar Mike Kravetz Committed by Linus Torvalds
Browse files

include/linux/hugetlb.h: add synchronization information for new hugetlb specific flags 

Add comments, no functional change.

Link: https://lkml.kernel.org/r/62a80585-2a73-10cc-4a2d-5721540d4ad2@oracle.com


Signed-off-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 6c037149

include/linux/hugetlb.h

+10 −0
Original line number Diff line number Diff line
@@ -480,14 +480,24 @@ unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, 
 * HPG_restore_reserve - Set when a hugetlb page consumes a reservation at

 *	allocation time.  Cleared when page is fully instantiated.  Free

 *	routine checks flag to restore a reservation on error paths.

 *	Synchronization:  Examined or modified by code that knows it has

 *	the only reference to page.  i.e. After allocation but before use

 *	or when the page is being freed.

 * HPG_migratable  - Set after a newly allocated page is added to the page

 *	cache and/or page tables.  Indicates the page is a candidate for

 *	migration.

 *	Synchronization:  Initially set after new page allocation with no

 *	locking.  When examined and modified during migration processing

 *	(isolate, migrate, putback) the hugetlb_lock is held.

 * HPG_temporary - - Set on a page that is temporarily allocated from the buddy

 *	allocator.  Typically used for migration target pages when no pages

 *	are available in the pool.  The hugetlb free page path will

 *	immediately free pages with this flag set to the buddy allocator.

 *	Synchronization: Can be set after huge page allocation from buddy when

 *	code knows it has only reference.  All other examinations and

 *	modifications require hugetlb_lock.

 * HPG_freed - Set when page is on the free lists.

 *	Synchronization: hugetlb_lock held for examination and modification.

 */

enum hugetlb_page_flags {

	HPG_restore_reserve = 0,