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Message-Id: <20210305041901.2396498-8-willy@infradead.org>
Date: Fri, 5 Mar 2021 04:18:43 +0000
From: "Matthew Wilcox (Oracle)" <willy@...radead.org>
To: linux-mm@...ck.org
Cc: "Matthew Wilcox (Oracle)" <willy@...radead.org>,
linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org
Subject: [PATCH v4 07/25] mm: Create FolioFlags
These new functions are the folio analogues of the PageFlags functions.
If CONFIG_DEBUG_VM_PGFLAGS is enabled, we check the folio is not a tail
page at every invocation. Note that this will also catch the PagePoisoned
case as a poisoned page has every bit set, which would include PageTail.
This saves 1740 bytes of text with the distro-derived config that
I'm testing due to removing a double call to compound_head() in
PageSwapCache().
Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
---
include/linux/fscache.h | 5 ++
include/linux/page-flags.h | 104 ++++++++++++++++++++++++++++++-------
2 files changed, 89 insertions(+), 20 deletions(-)
diff --git a/include/linux/fscache.h b/include/linux/fscache.h
index a1c928fe98e7..c274006f4037 100644
--- a/include/linux/fscache.h
+++ b/include/linux/fscache.h
@@ -38,6 +38,11 @@
#define ClearPageFsCache(page) ClearPagePrivate2((page))
#define TestSetPageFsCache(page) TestSetPagePrivate2((page))
#define TestClearPageFsCache(page) TestClearPagePrivate2((page))
+#define FolioFsCache(folio) FolioPrivate2((folio))
+#define SetFolioFsCache(folio) SetFolioPrivate2((folio))
+#define ClearFolioFsCache(folio) ClearFolioPrivate2((folio))
+#define TestSetFolioFsCache(folio) TestSetFolioPrivate2((folio))
+#define TestClearFolioFsCache(folio) TestClearFolioPrivate2((folio))
/* pattern used to fill dead space in an index entry */
#define FSCACHE_INDEX_DEADFILL_PATTERN 0x79
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 04a34c08e0a6..90381858d901 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -212,6 +212,12 @@ static inline void page_init_poison(struct page *page, size_t size)
}
#endif
+static unsigned long *folio_flags(struct folio *folio)
+{
+ VM_BUG_ON_PGFLAGS(PageTail(&folio->page), &folio->page);
+ return &folio->page.flags;
+}
+
/*
* Page flags policies wrt compound pages
*
@@ -260,30 +266,44 @@ 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 Folio##uname(struct folio *folio) \
+ { return test_bit(PG_##lname, folio_flags(folio)); } \
static __always_inline int Page##uname(struct page *page) \
{ return test_bit(PG_##lname, &policy(page, 0)->flags); }
#define SETPAGEFLAG(uname, lname, policy) \
+static __always_inline void SetFolio##uname(struct folio *folio) \
+ { set_bit(PG_##lname, folio_flags(folio)); } \
static __always_inline void SetPage##uname(struct page *page) \
{ set_bit(PG_##lname, &policy(page, 1)->flags); }
#define CLEARPAGEFLAG(uname, lname, policy) \
+static __always_inline void ClearFolio##uname(struct folio *folio) \
+ { clear_bit(PG_##lname, folio_flags(folio)); } \
static __always_inline void ClearPage##uname(struct page *page) \
{ clear_bit(PG_##lname, &policy(page, 1)->flags); }
#define __SETPAGEFLAG(uname, lname, policy) \
+static __always_inline void __SetFolio##uname(struct folio *folio) \
+ { __set_bit(PG_##lname, folio_flags(folio)); } \
static __always_inline void __SetPage##uname(struct page *page) \
{ __set_bit(PG_##lname, &policy(page, 1)->flags); }
#define __CLEARPAGEFLAG(uname, lname, policy) \
+static __always_inline void __ClearFolio##uname(struct folio *folio) \
+ { __clear_bit(PG_##lname, folio_flags(folio)); } \
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 TestSetFolio##uname(struct folio *folio) \
+ { return test_and_set_bit(PG_##lname, folio_flags(folio)); } \
static __always_inline int 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 TestClearFolio##uname(struct folio *folio) \
+ { return test_and_clear_bit(PG_##lname, folio_flags(folio)); } \
static __always_inline int TestClearPage##uname(struct page *page) \
{ return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); }
@@ -302,21 +322,27 @@ static __always_inline int TestClearPage##uname(struct page *page) \
TESTCLEARFLAG(uname, lname, policy)
#define TESTPAGEFLAG_FALSE(uname) \
+static inline int Folio##uname(const struct folio *folio) { return 0; } \
static inline int Page##uname(const struct page *page) { return 0; }
#define SETPAGEFLAG_NOOP(uname) \
+static inline void SetFolio##uname(struct folio *folio) { } \
static inline void SetPage##uname(struct page *page) { }
#define CLEARPAGEFLAG_NOOP(uname) \
+static inline void ClearFolio##uname(struct folio *folio) { } \
static inline void ClearPage##uname(struct page *page) { }
#define __CLEARPAGEFLAG_NOOP(uname) \
+static inline void __ClearFolio##uname(struct folio *folio) { } \
static inline void __ClearPage##uname(struct page *page) { }
#define TESTSETFLAG_FALSE(uname) \
+static inline int TestSetFolio##uname(struct folio *folio) { return 0; } \
static inline int TestSetPage##uname(struct page *page) { return 0; }
#define TESTCLEARFLAG_FALSE(uname) \
+static inline int TestClearFolio##uname(struct folio *folio) { return 0; } \
static inline int TestClearPage##uname(struct page *page) { return 0; }
#define PAGEFLAG_FALSE(uname) TESTPAGEFLAG_FALSE(uname) \
@@ -393,14 +419,18 @@ PAGEFLAG_FALSE(HighMem)
#endif
#ifdef CONFIG_SWAP
-static __always_inline int PageSwapCache(struct page *page)
+static __always_inline bool FolioSwapCache(struct folio *folio)
{
-#ifdef CONFIG_THP_SWAP
- page = compound_head(page);
-#endif
- return PageSwapBacked(page) && test_bit(PG_swapcache, &page->flags);
+ return FolioSwapBacked(folio) &&
+ test_bit(PG_swapcache, folio_flags(folio));
}
+
+static __always_inline bool PageSwapCache(struct page *page)
+{
+ return FolioSwapCache(page_folio(page));
+}
+
SETPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL)
CLEARPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL)
#else
@@ -478,10 +508,14 @@ static __always_inline int 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 FolioAnon(struct folio *folio)
{
- page = compound_head(page);
- return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0;
+ return ((unsigned long)folio->page.mapping & PAGE_MAPPING_ANON) != 0;
+}
+
+static __always_inline bool PageAnon(struct page *page)
+{
+ return FolioAnon(page_folio(page));
}
static __always_inline int __PageMovable(struct page *page)
@@ -509,18 +543,16 @@ TESTPAGEFLAG_FALSE(Ksm)
u64 stable_page_flags(struct page *page);
-static inline int PageUptodate(struct page *page)
+static inline int FolioUptodate(struct folio *folio)
{
- int ret;
- page = compound_head(page);
- ret = test_bit(PG_uptodate, &(page)->flags);
+ int ret = test_bit(PG_uptodate, folio_flags(folio));
/*
* Must ensure that the data we read out of the page is loaded
* _after_ we've loaded page->flags to check for PageUptodate.
* We can skip the barrier if the page is not uptodate, because
* we wouldn't be reading anything from it.
*
- * See SetPageUptodate() for the other side of the story.
+ * See SetFolioUptodate() for the other side of the story.
*/
if (ret)
smp_rmb();
@@ -528,23 +560,36 @@ static inline int PageUptodate(struct page *page)
return ret;
}
-static __always_inline void __SetPageUptodate(struct page *page)
+static inline int PageUptodate(struct page *page)
+{
+ return FolioUptodate(page_folio(page));
+}
+
+static __always_inline void __SetFolioUptodate(struct folio *folio)
{
- VM_BUG_ON_PAGE(PageTail(page), page);
smp_wmb();
- __set_bit(PG_uptodate, &page->flags);
+ __set_bit(PG_uptodate, folio_flags(folio));
}
-static __always_inline void SetPageUptodate(struct page *page)
+static __always_inline void SetFolioUptodate(struct folio *folio)
{
- VM_BUG_ON_PAGE(PageTail(page), page);
/*
* Memory barrier must be issued before setting the PG_uptodate bit,
* so that all previous stores issued in order to bring the page
* uptodate are actually visible before PageUptodate becomes true.
*/
smp_wmb();
- set_bit(PG_uptodate, &page->flags);
+ set_bit(PG_uptodate, folio_flags(folio));
+}
+
+static __always_inline void __SetPageUptodate(struct page *page)
+{
+ __SetFolioUptodate((struct folio *)page);
+}
+
+static __always_inline void SetPageUptodate(struct page *page)
+{
+ SetFolioUptodate((struct folio *)page);
}
CLEARPAGEFLAG(Uptodate, uptodate, PF_NO_TAIL)
@@ -569,6 +614,17 @@ static inline void set_page_writeback_keepwrite(struct page *page)
__PAGEFLAG(Head, head, PF_ANY) CLEARPAGEFLAG(Head, head, PF_ANY)
+/* Whether there are one or multiple pages in a folio */
+static inline bool FolioSingle(struct folio *folio)
+{
+ return !FolioHead(folio);
+}
+
+static inline bool FolioMulti(struct folio *folio)
+{
+ return FolioHead(folio);
+}
+
static __always_inline void set_compound_head(struct page *page, struct page *head)
{
WRITE_ONCE(page->compound_head, (unsigned long)head + 1);
@@ -592,12 +648,15 @@ static inline void ClearPageCompound(struct page *page)
#ifdef CONFIG_HUGETLB_PAGE
int PageHuge(struct page *page);
int PageHeadHuge(struct page *page);
+static inline bool FolioHuge(struct folio *folio)
+{
+ return PageHeadHuge(&folio->page);
+}
#else
TESTPAGEFLAG_FALSE(Huge)
TESTPAGEFLAG_FALSE(HeadHuge)
#endif
-
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
/*
* PageHuge() only returns true for hugetlbfs pages, but not for
@@ -844,6 +903,11 @@ static inline int page_has_private(struct page *page)
return !!(page->flags & PAGE_FLAGS_PRIVATE);
}
+static inline bool folio_has_private(struct folio *folio)
+{
+ return page_has_private(&folio->page);
+}
+
#undef PF_ANY
#undef PF_HEAD
#undef PF_ONLY_HEAD
--
2.30.0
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