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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/page_owner.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/page_owner.c')
| -rw-r--r-- | mm/page_owner.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/mm/page_owner.c b/mm/page_owner.c index 220cdeddc295..31169b3e7f06 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -315,7 +315,7 @@ void pagetypeinfo_showmixedcount_print(struct seq_file *m, unsigned long freepage_order; freepage_order = buddy_order_unsafe(page); - if (freepage_order < MAX_ORDER) + if (freepage_order <= MAX_ORDER) pfn += (1UL << freepage_order) - 1; continue; } @@ -549,7 +549,7 @@ read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos) if (PageBuddy(page)) { unsigned long freepage_order = buddy_order_unsafe(page); - if (freepage_order < MAX_ORDER) + if (freepage_order <= MAX_ORDER) pfn += (1UL << freepage_order) - 1; continue; } @@ -657,7 +657,7 @@ static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone) if (PageBuddy(page)) { unsigned long order = buddy_order_unsafe(page); - if (order > 0 && order < MAX_ORDER) + if (order > 0 && order <= MAX_ORDER) pfn += (1UL << order) - 1; continue; } |