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| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2023-03-15 14:31:33 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-04-05 19:42:46 -0700 |
| commit | 23baf831a32c04f9a968812511540b1b3e648bf5 (patch) | |
| tree | fcaca52cefbef2707710ce057f58fb1c955a0559 /mm/memory_hotplug.c | |
| parent | 61883d3c32418f16e35e030ca0cfd5d2de95a649 (diff) | |
| download | lwn-23baf831a32c04f9a968812511540b1b3e648bf5.tar.gz lwn-23baf831a32c04f9a968812511540b1b3e648bf5.zip | |
mm, treewide: redefine MAX_ORDER sanely
MAX_ORDER currently defined as number of orders page allocator supports:
user can ask buddy allocator for page order between 0 and MAX_ORDER-1.
This definition is counter-intuitive and lead to number of bugs all over
the kernel.
Change the definition of MAX_ORDER to be inclusive: the range of orders
user can ask from buddy allocator is 0..MAX_ORDER now.
[kirill@shutemov.name: fix min() warning]
Link: https://lkml.kernel.org/r/20230315153800.32wib3n5rickolvh@box
[akpm@linux-foundation.org: fix another min_t warning]
[kirill@shutemov.name: fixups per Zi Yan]
Link: https://lkml.kernel.org/r/20230316232144.b7ic4cif4kjiabws@box.shutemov.name
[akpm@linux-foundation.org: fix underlining in docs]
Link: https://lore.kernel.org/oe-kbuild-all/202303191025.VRCTk6mP-lkp@intel.com/
Link: https://lkml.kernel.org/r/20230315113133.11326-11-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc]
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/memory_hotplug.c')
| -rw-r--r-- | mm/memory_hotplug.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index db3b270254f1..c8f0a8c2d049 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -596,7 +596,7 @@ static void online_pages_range(unsigned long start_pfn, unsigned long nr_pages) unsigned long pfn; /* - * Online the pages in MAX_ORDER - 1 aligned chunks. The callback might + * Online the pages in MAX_ORDER aligned chunks. The callback might * decide to not expose all pages to the buddy (e.g., expose them * later). We account all pages as being online and belonging to this * zone ("present"). @@ -605,7 +605,7 @@ static void online_pages_range(unsigned long start_pfn, unsigned long nr_pages) * this and the first chunk to online will be pageblock_nr_pages. */ for (pfn = start_pfn; pfn < end_pfn;) { - int order = min(MAX_ORDER - 1UL, __ffs(pfn)); + int order = min_t(int, MAX_ORDER, __ffs(pfn)); (*online_page_callback)(pfn_to_page(pfn), order); pfn += (1UL << order); |