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| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2020-10-13 16:53:54 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-13 18:38:31 -0700 |
| commit | a08d93e5752a35a771054f6c463f789720f9a3e8 (patch) | |
| tree | 8cc99136ba5c89cb01912f3ca0ac7417e766a450 /include/linux/page-flags.h | |
| parent | e18c45ffcfa347b13c2f300f290bacff55a4b41e (diff) | |
| download | lwn-a08d93e5752a35a771054f6c463f789720f9a3e8.tar.gz lwn-a08d93e5752a35a771054f6c463f789720f9a3e8.zip | |
mm: simplify PageDoubleMap with PF_SECOND policy
Introduce the new page policy of PF_SECOND which lets us use the normal
pageflags generation machinery to create the various DoubleMap
manipulation functions.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Link: https://lkml.kernel.org/r/20200629151933.15671-3-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/page-flags.h')
| -rw-r--r-- | include/linux/page-flags.h | 40 |
1 files changed, 10 insertions, 30 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 76413b2ffef0..38ded408bd4c 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -235,6 +235,9 @@ static inline void page_init_poison(struct page *page, size_t size) * * PF_NO_COMPOUND: * the page flag is not relevant for compound pages. + * + * PF_SECOND: + * the page flag is stored in the first tail page. */ #define PF_POISONED_CHECK(page) ({ \ VM_BUG_ON_PGFLAGS(PagePoisoned(page), page); \ @@ -250,6 +253,9 @@ static inline void page_init_poison(struct page *page, size_t size) #define PF_NO_COMPOUND(page, enforce) ({ \ VM_BUG_ON_PGFLAGS(enforce && PageCompound(page), page); \ PF_POISONED_CHECK(page); }) +#define PF_SECOND(page, enforce) ({ \ + VM_BUG_ON_PGFLAGS(!PageHead(page), page); \ + PF_POISONED_CHECK(&page[1]); }) /* * Macros to create function definitions for page flags @@ -688,42 +694,15 @@ static inline int PageTransTail(struct page *page) * * See also __split_huge_pmd_locked() and page_remove_anon_compound_rmap(). */ -static inline int PageDoubleMap(struct page *page) -{ - return PageHead(page) && test_bit(PG_double_map, &page[1].flags); -} - -static inline void SetPageDoubleMap(struct page *page) -{ - VM_BUG_ON_PAGE(!PageHead(page), page); - set_bit(PG_double_map, &page[1].flags); -} - -static inline void ClearPageDoubleMap(struct page *page) -{ - VM_BUG_ON_PAGE(!PageHead(page), page); - clear_bit(PG_double_map, &page[1].flags); -} -static inline int TestSetPageDoubleMap(struct page *page) -{ - VM_BUG_ON_PAGE(!PageHead(page), page); - return test_and_set_bit(PG_double_map, &page[1].flags); -} - -static inline int TestClearPageDoubleMap(struct page *page) -{ - VM_BUG_ON_PAGE(!PageHead(page), page); - return test_and_clear_bit(PG_double_map, &page[1].flags); -} - +PAGEFLAG(DoubleMap, double_map, PF_SECOND) + TESTSCFLAG(DoubleMap, double_map, PF_SECOND) #else TESTPAGEFLAG_FALSE(TransHuge) TESTPAGEFLAG_FALSE(TransCompound) TESTPAGEFLAG_FALSE(TransCompoundMap) TESTPAGEFLAG_FALSE(TransTail) PAGEFLAG_FALSE(DoubleMap) - TESTSETFLAG_FALSE(DoubleMap) - TESTCLEARFLAG_FALSE(DoubleMap) + TESTSCFLAG_FALSE(DoubleMap) #endif /* @@ -888,6 +867,7 @@ static inline int page_has_private(struct page *page) #undef PF_ONLY_HEAD #undef PF_NO_TAIL #undef PF_NO_COMPOUND +#undef PF_SECOND #endif /* !__GENERATING_BOUNDS_H */ #endif /* PAGE_FLAGS_H */ |