[136/227] mm/hugetlb.c: export PageHeadHuge()

Commit Message

Andrew Morton March 22, 2022, 9:45 p.m. UTC

From: David Howells <[e-mail]>
Subject: mm/hugetlb.c: export PageHeadHuge()

Export PageHeadHuge() - it's used by folio_test_hugetlb() and thence by
such as folio_file_page() and folio_contains().  Matthew suggested I use
the first of those instead of doing the same calculation manually - but I
can't call it from a module.

Kirill suggested rearranging things to put it in a header, but that
introduces header dependencies because of where constants are defined.

[[e-mail]: s/EXPORT_SYMBOL/EXPORT_SYMBOL_GPL/, per Christoph]
Link: https://lkml.kernel.org/r/[e-mail]
Link: https://lore.kernel.org/r/[e-mail]/
Signed-off-by: David Howells <[e-mail]>
Cc: Matthew Wilcox (Oracle) <[e-mail]>
Cc: Kirill A. Shutemov <[e-mail]>
Cc: Christoph Hellwig <[e-mail]>
Cc: Mike Kravetz <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 mm/hugetlb.c |    1 +
 1 file changed, 1 insertion(+)

Patch

--- a/mm/hugetlb.c~mm-export-pageheadhuge
+++ a/mm/hugetlb.c
@@ -1855,6 +1855,7 @@  int PageHeadHuge(struct page *page_head)
 
 	return page_head[1].compound_dtor == HUGETLB_PAGE_DTOR;
 }
+EXPORT_SYMBOL_GPL(PageHeadHuge);
 
 /*
  * Find and lock address space (mapping) in write mode.