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authorMatthew Wilcox (Oracle) <[email protected]>2024-08-21 18:39:10 +0100
committerAndrew Morton <[email protected]>2024-09-03 21:15:42 -0700
commite880034cf7182aa35962bd30dfc9fa60476d56a4 (patch)
tree55148be6aa56f0c4bf523dc7c6df26135454499c
parente27ad6560e4b5993315b56d6884ca5a4652468f4 (diff)
mm: introduce page_mapcount_is_type()
Resolve the awkward "and add one to this opaque constant" test into a self-documenting inline function. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Matthew Wilcox (Oracle) <[email protected]> Acked-by: David Hildenbrand <[email protected]> Cc: Hyeonggon Yoo <[email protected]> Cc: Kent Overstreet <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
-rw-r--r--fs/proc/internal.h3
-rw-r--r--include/linux/mm.h3
-rw-r--r--include/linux/page-flags.h12
3 files changed, 11 insertions, 7 deletions
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index a8a8576d8592..cc520168f8b6 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -166,8 +166,7 @@ static inline int folio_precise_page_mapcount(struct folio *folio,
{
int mapcount = atomic_read(&page->_mapcount) + 1;
- /* Handle page_has_type() pages */
- if (mapcount < PAGE_MAPCOUNT_RESERVE + 1)
+ if (page_mapcount_is_type(mapcount))
mapcount = 0;
if (folio_test_large(folio))
mapcount += folio_entire_mapcount(folio);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 0fde51c0532f..6f6053d7ea6f 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1228,8 +1228,7 @@ static inline int folio_mapcount(const struct folio *folio)
if (likely(!folio_test_large(folio))) {
mapcount = atomic_read(&folio->_mapcount) + 1;
- /* Handle page_has_type() pages */
- if (mapcount < PAGE_MAPCOUNT_RESERVE + 1)
+ if (page_mapcount_is_type(mapcount))
mapcount = 0;
return mapcount;
}
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 2515ae85f191..0b5484fdbca1 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -956,12 +956,18 @@ enum pagetype {
#define folio_test_type(folio, flag) \
((READ_ONCE(folio->page.page_type) & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE)
-static inline int page_type_has_type(unsigned int page_type)
+static inline bool page_type_has_type(int page_type)
{
- return (int)page_type < PAGE_MAPCOUNT_RESERVE;
+ return page_type < PAGE_MAPCOUNT_RESERVE;
}
-static inline int page_has_type(const struct page *page)
+/* This takes a mapcount which is one more than page->_mapcount */
+static inline bool page_mapcount_is_type(unsigned int mapcount)
+{
+ return page_type_has_type(mapcount - 1);
+}
+
+static inline bool page_has_type(const struct page *page)
{
return page_type_has_type(READ_ONCE(page->page_type));
}