From: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Sat, 15 Aug 2020 00:30:43 +0000 (-0700)
Subject: mm: introduce offset_in_thp
X-Git-Tag: baikal/mips/sdk5.9~12890^2~22
X-Git-Url: https://git.baikalelectronics.ru/?a=commitdiff_plain;h=1dcee7f5db0d58757aedafbb9962612490115f9b;p=kernel.git

mm: introduce offset_in_thp

Mirroring offset_in_page(), this gives you the offset within this
particular page, no matter what size page it is.  It optimises down to
offset_in_page() if CONFIG_TRANSPARENT_HUGEPAGE is not set.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Link: http://lkml.kernel.org/r/20200629151959.15779-8-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/include/linux/mm.h b/include/linux/mm.h
index fd0cd4e93029d..2e7ec3ee34cf6 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1594,6 +1594,7 @@ static inline void clear_page_pfmemalloc(struct page *page)
 extern void pagefault_out_of_memory(void);
 
 #define offset_in_page(p)	((unsigned long)(p) & ~PAGE_MASK)
+#define offset_in_thp(page, p)	((unsigned long)(p) & (thp_size(page) - 1))
 
 /*
  * Flags passed to show_mem() and show_free_areas() to suppress output in