[RFC PATCH 2/3] mm: Return bool from pagebit test functions
From: David Howells
Date: Fri Apr 09 2021 - 06:59:40 EST
Make functions that test page bits return a bool, not an int. This means
that the value is definitely 0 or 1 if they're used in arithmetic, rather
than rely on test_bit() and friends to return this (though they probably
should).
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
cc: linux-mm@xxxxxxxxx
cc: linux-fsdevel@xxxxxxxxxxxxxxx
---
include/linux/page-flags.h | 50 ++++++++++++++++++++++----------------------
1 file changed, 25 insertions(+), 25 deletions(-)
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 04a34c08e0a6..4ff7de61b13d 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -188,18 +188,18 @@ static inline struct page *compound_head(struct page *page)
return page;
}
-static __always_inline int PageTail(struct page *page)
+static __always_inline bool PageTail(struct page *page)
{
return READ_ONCE(page->compound_head) & 1;
}
-static __always_inline int PageCompound(struct page *page)
+static __always_inline bool PageCompound(struct page *page)
{
return test_bit(PG_head, &page->flags) || PageTail(page);
}
#define PAGE_POISON_PATTERN -1l
-static inline int PagePoisoned(const struct page *page)
+static inline bool PagePoisoned(const struct page *page)
{
return page->flags == PAGE_POISON_PATTERN;
}
@@ -260,7 +260,7 @@ static inline void page_init_poison(struct page *page, size_t size)
* Macros to create function definitions for page flags
*/
#define TESTPAGEFLAG(uname, lname, policy) \
-static __always_inline int Page##uname(struct page *page) \
+static __always_inline bool Page##uname(struct page *page) \
{ return test_bit(PG_##lname, &policy(page, 0)->flags); }
#define SETPAGEFLAG(uname, lname, policy) \
@@ -280,11 +280,11 @@ static __always_inline void __ClearPage##uname(struct page *page) \
{ __clear_bit(PG_##lname, &policy(page, 1)->flags); }
#define TESTSETFLAG(uname, lname, policy) \
-static __always_inline int TestSetPage##uname(struct page *page) \
+static __always_inline bool TestSetPage##uname(struct page *page) \
{ return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); }
#define TESTCLEARFLAG(uname, lname, policy) \
-static __always_inline int TestClearPage##uname(struct page *page) \
+static __always_inline bool TestClearPage##uname(struct page *page) \
{ return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); }
#define PAGEFLAG(uname, lname, policy) \
@@ -302,7 +302,7 @@ static __always_inline int TestClearPage##uname(struct page *page) \
TESTCLEARFLAG(uname, lname, policy)
#define TESTPAGEFLAG_FALSE(uname) \
-static inline int Page##uname(const struct page *page) { return 0; }
+static inline bool Page##uname(const struct page *page) { return false; }
#define SETPAGEFLAG_NOOP(uname) \
static inline void SetPage##uname(struct page *page) { }
@@ -314,10 +314,10 @@ static inline void ClearPage##uname(struct page *page) { }
static inline void __ClearPage##uname(struct page *page) { }
#define TESTSETFLAG_FALSE(uname) \
-static inline int TestSetPage##uname(struct page *page) { return 0; }
+static inline bool TestSetPage##uname(struct page *page) { return false; }
#define TESTCLEARFLAG_FALSE(uname) \
-static inline int TestClearPage##uname(struct page *page) { return 0; }
+static inline bool TestClearPage##uname(struct page *page) { return false; }
#define PAGEFLAG_FALSE(uname) TESTPAGEFLAG_FALSE(uname) \
SETPAGEFLAG_NOOP(uname) CLEARPAGEFLAG_NOOP(uname)
@@ -393,7 +393,7 @@ PAGEFLAG_FALSE(HighMem)
#endif
#ifdef CONFIG_SWAP
-static __always_inline int PageSwapCache(struct page *page)
+static __always_inline bool PageSwapCache(struct page *page)
{
#ifdef CONFIG_THP_SWAP
page = compound_head(page);
@@ -473,18 +473,18 @@ __PAGEFLAG(Reported, reported, PF_NO_COMPOUND)
#define PAGE_MAPPING_KSM (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE)
#define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE)
-static __always_inline int PageMappingFlags(struct page *page)
+static __always_inline bool PageMappingFlags(struct page *page)
{
return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) != 0;
}
-static __always_inline int PageAnon(struct page *page)
+static __always_inline bool PageAnon(struct page *page)
{
page = compound_head(page);
return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0;
}
-static __always_inline int __PageMovable(struct page *page)
+static __always_inline bool __PageMovable(struct page *page)
{
return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) ==
PAGE_MAPPING_MOVABLE;
@@ -497,7 +497,7 @@ static __always_inline int __PageMovable(struct page *page)
* is found in VM_MERGEABLE vmas. It's a PageAnon page, pointing not to any
* anon_vma, but to that page's node of the stable tree.
*/
-static __always_inline int PageKsm(struct page *page)
+static __always_inline bool PageKsm(struct page *page)
{
page = compound_head(page);
return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) ==
@@ -509,9 +509,9 @@ TESTPAGEFLAG_FALSE(Ksm)
u64 stable_page_flags(struct page *page);
-static inline int PageUptodate(struct page *page)
+static inline bool PageUptodate(struct page *page)
{
- int ret;
+ bool ret;
page = compound_head(page);
ret = test_bit(PG_uptodate, &(page)->flags);
/*
@@ -607,7 +607,7 @@ TESTPAGEFLAG_FALSE(HeadHuge)
* hugetlbfs pages, but not normal pages. PageTransHuge() can only be
* called only in the core VM paths where hugetlbfs pages can't exist.
*/
-static inline int PageTransHuge(struct page *page)
+static inline bool PageTransHuge(struct page *page)
{
VM_BUG_ON_PAGE(PageTail(page), page);
return PageHead(page);
@@ -618,7 +618,7 @@ static inline int PageTransHuge(struct page *page)
* and hugetlbfs pages, so it should only be called when it's known
* that hugetlbfs pages aren't involved.
*/
-static inline int PageTransCompound(struct page *page)
+static inline bool PageTransCompound(struct page *page)
{
return PageCompound(page);
}
@@ -644,12 +644,12 @@ static inline int PageTransCompound(struct page *page)
* mapped in the current process so comparing subpage's _mapcount to
* compound_mapcount to filter out PTE mapped case.
*/
-static inline int PageTransCompoundMap(struct page *page)
+static inline bool PageTransCompoundMap(struct page *page)
{
struct page *head;
if (!PageTransCompound(page))
- return 0;
+ return false;
if (PageAnon(page))
return atomic_read(&page->_mapcount) < 0;
@@ -665,7 +665,7 @@ static inline int PageTransCompoundMap(struct page *page)
* and hugetlbfs pages, so it should only be called when it's known
* that hugetlbfs pages aren't involved.
*/
-static inline int PageTransTail(struct page *page)
+static inline bool PageTransTail(struct page *page)
{
return PageTail(page);
}
@@ -714,13 +714,13 @@ PAGEFLAG_FALSE(DoubleMap)
#define PageType(page, flag) \
((page->page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE)
-static inline int page_has_type(struct page *page)
+static inline bool page_has_type(struct page *page)
{
return (int)page->page_type < PAGE_MAPCOUNT_RESERVE;
}
#define PAGE_TYPE_OPS(uname, lname) \
-static __always_inline int Page##uname(struct page *page) \
+static __always_inline bool Page##uname(struct page *page) \
{ \
return PageType(page, PG_##lname); \
} \
@@ -778,7 +778,7 @@ __PAGEFLAG(Isolated, isolated, PF_ANY);
* If network-based swap is enabled, sl*b must keep track of whether pages
* were allocated from pfmemalloc reserves.
*/
-static inline int PageSlabPfmemalloc(struct page *page)
+static inline bool PageSlabPfmemalloc(struct page *page)
{
VM_BUG_ON_PAGE(!PageSlab(page), page);
return PageActive(page);
@@ -839,7 +839,7 @@ static inline void ClearPageSlabPfmemalloc(struct page *page)
* Determine if a page has private stuff, indicating that release routines
* should be invoked upon it.
*/
-static inline int page_has_private(struct page *page)
+static inline bool page_has_private(struct page *page)
{
return !!(page->flags & PAGE_FLAGS_PRIVATE);
}