diff options
| author | Richard Weinberger <richard@nod.at> | 2025-11-22 22:19:20 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-11-24 15:08:56 -0800 |
| commit | 84a8d467cc426eb3c9eb34092423dcc54493dd7e (patch) | |
| tree | 4a42fba4ff04a042c49729031b3a2f25c73f06b6 /Documentation/admin-guide | |
| parent | b7dd80f8f92848fa26518119f2c378dad8b7c0da (diff) | |
pagemap: update BUDDY flag documentation
Since v4.6 the BUDDY flag is set for _all_ pages in the block
and no longer just for the first one.
This change was introduced by:
commit 832fc1de01ae ("/proc/kpageflags: return KPF_BUDDY for "tail" buddy pages")
Strictly speaking, this was an ABI change, but as nobody has noticed
since 2016, let's just update the documentation.
Link: https://lkml.kernel.org/r/20251122211920.3410371-1-richard@nod.at
Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/mm/pagemap.rst | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/Documentation/admin-guide/mm/pagemap.rst b/Documentation/admin-guide/mm/pagemap.rst index e60e9211fd9b..c57e61b5d8aa 100644 --- a/Documentation/admin-guide/mm/pagemap.rst +++ b/Documentation/admin-guide/mm/pagemap.rst @@ -115,7 +115,8 @@ Short descriptions to the page flags A free memory block managed by the buddy system allocator. The buddy system organizes free memory in blocks of various orders. An order N block has 2^N physically contiguous pages, with the BUDDY flag - set for and _only_ for the first page. + set for all pages. + Before 4.6 only the first page of the block had the flag set. 15 - COMPOUND_HEAD A compound page with order N consists of 2^N physically contiguous pages. A compound page with order 2 takes the form of "HTTT", where H donates its |