diff options
| author | Mike Kravetz | 2021-02-24 12:09:08 -0800 |
|---|---|---|
| committer | Linus Torvalds | 2021-02-24 13:38:34 -0800 |
| commit | d95c0337774b1dc74d271e7475a96fe8838332ea (patch) | |
| tree | e8e9a554c484ae306ec0d65c475799e8dc0b2d41 /include/linux/hugetlb.h | |
| parent | 6c037149014027d50175da5be4ae4531374dcbe0 (diff) | |
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: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/hugetlb.h')
| -rw-r--r-- | include/linux/hugetlb.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index eb2682fd97b6..3a541c6cf5c3 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -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, |