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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2023-03-15 14:31:33 +0300
committerAndrew Morton <akpm@linux-foundation.org>2023-04-05 19:42:46 -0700
commit23baf831a32c04f9a968812511540b1b3e648bf5 (patch)
treefcaca52cefbef2707710ce057f58fb1c955a0559 /mm/memory_hotplug.c
parent61883d3c32418f16e35e030ca0cfd5d2de95a649 (diff)
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.c4
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);