PG_active,
PG_slab,
PG_owner_priv_1, /* Owner use. If pagecache, fs may use*/
- PG_checked = PG_owner_priv_1, /* Used by some filesystems */
- PG_pinned = PG_owner_priv_1, /* Xen pinned pagetable */
PG_arch_1,
PG_reserved,
PG_private, /* If pagecache, has fs-private data */
PG_writeback, /* Page is under writeback */
+#ifdef CONFIG_PAGEFLAGS_EXTENDED
+ PG_head, /* A head page */
+ PG_tail, /* A tail page */
+#else
PG_compound, /* A compound page */
+#endif
PG_swapcache, /* Swap page: swp_entry_t in private */
PG_mappedtodisk, /* Has blocks allocated on-disk */
PG_reclaim, /* To be reclaimed asap */
- /* PG_readahead is only used for file reads; PG_reclaim is only for writes */
- PG_readahead = PG_reclaim, /* Reminder to do async read-ahead */
PG_buddy, /* Page is free, on buddy lists */
-
-#if (BITS_PER_LONG > 32)
-/*
- * 64-bit-only flags build down from bit 31
- *
- * 32 bit -------------------------------| FIELDS | FLAGS |
- * 64 bit | FIELDS | ?????? FLAGS |
- * 63 32 0
- */
- PG_uncached = 31, /* Page has been mapped as uncached */
+#ifdef CONFIG_IA64_UNCACHED_ALLOCATOR
+ PG_uncached, /* Page has been mapped as uncached */
#endif
__NR_PAGEFLAGS
};
#define __PAGEFLAG(uname, lname) TESTPAGEFLAG(uname, lname) \
__SETPAGEFLAG(uname, lname) __CLEARPAGEFLAG(uname, lname)
+#define PAGEFLAG_FALSE(uname) \
+static inline int Page##uname(struct page *page) \
+ { return 0; }
+
#define TESTSCFLAG(uname, lname) \
TESTSETFLAG(uname, lname) TESTCLEARFLAG(uname, lname)
+struct page; /* forward declaration */
+
+PAGEFLAG(Locked, locked) TESTSCFLAG(Locked, locked)
+PAGEFLAG(Error, error)
+PAGEFLAG(Referenced, referenced) TESTCLEARFLAG(Referenced, referenced)
+PAGEFLAG(Dirty, dirty) TESTSCFLAG(Dirty, dirty) __CLEARPAGEFLAG(Dirty, dirty)
+PAGEFLAG(LRU, lru) __CLEARPAGEFLAG(LRU, lru)
+PAGEFLAG(Active, active) __CLEARPAGEFLAG(Active, active)
+__PAGEFLAG(Slab, slab)
+PAGEFLAG(Checked, owner_priv_1) /* Used by some filesystems */
+PAGEFLAG(Pinned, owner_priv_1) TESTSCFLAG(Pinned, owner_priv_1) /* Xen */
+PAGEFLAG(SavePinned, dirty); /* Xen */
+PAGEFLAG(Reserved, reserved) __CLEARPAGEFLAG(Reserved, reserved)
+PAGEFLAG(Private, private) __CLEARPAGEFLAG(Private, private)
+ __SETPAGEFLAG(Private, private)
+
/*
- * Manipulation of page state flags
+ * Only test-and-set exist for PG_writeback. The unconditional operators are
+ * risky: they bypass page accounting.
*/
-#define PageLocked(page) \
- test_bit(PG_locked, &(page)->flags)
-#define SetPageLocked(page) \
- set_bit(PG_locked, &(page)->flags)
-#define TestSetPageLocked(page) \
- test_and_set_bit(PG_locked, &(page)->flags)
-#define ClearPageLocked(page) \
- clear_bit(PG_locked, &(page)->flags)
-#define TestClearPageLocked(page) \
- test_and_clear_bit(PG_locked, &(page)->flags)
-
-#define PageError(page) test_bit(PG_error, &(page)->flags)
-#define SetPageError(page) set_bit(PG_error, &(page)->flags)
-#define ClearPageError(page) clear_bit(PG_error, &(page)->flags)
-
-#define PageReferenced(page) test_bit(PG_referenced, &(page)->flags)
-#define SetPageReferenced(page) set_bit(PG_referenced, &(page)->flags)
-#define ClearPageReferenced(page) clear_bit(PG_referenced, &(page)->flags)
-#define TestClearPageReferenced(page) test_and_clear_bit(PG_referenced, &(page)->flags)
+TESTPAGEFLAG(Writeback, writeback) TESTSCFLAG(Writeback, writeback)
+__PAGEFLAG(Buddy, buddy)
+PAGEFLAG(MappedToDisk, mappedtodisk)
+
+/* PG_readahead is only used for file reads; PG_reclaim is only for writes */
+PAGEFLAG(Reclaim, reclaim) TESTCLEARFLAG(Reclaim, reclaim)
+PAGEFLAG(Readahead, reclaim) /* Reminder to do async read-ahead */
+
+#ifdef CONFIG_HIGHMEM
+/*
+ * Must use a macro here due to header dependency issues. page_zone() is not
+ * available at this point.
+ */
+#define PageHighMem(__p) is_highmem(page_zone(__p))
+#else
+PAGEFLAG_FALSE(HighMem)
+#endif
+
+#ifdef CONFIG_SWAP
+PAGEFLAG(SwapCache, swapcache)
+#else
+PAGEFLAG_FALSE(SwapCache)
+#endif
+
+#ifdef CONFIG_IA64_UNCACHED_ALLOCATOR
+PAGEFLAG(Uncached, uncached)
+#else
+PAGEFLAG_FALSE(Uncached)
+#endif
static inline int PageUptodate(struct page *page)
{
#endif
}
-#define ClearPageUptodate(page) clear_bit(PG_uptodate, &(page)->flags)
-
-#define PageDirty(page) test_bit(PG_dirty, &(page)->flags)
-#define SetPageDirty(page) set_bit(PG_dirty, &(page)->flags)
-#define TestSetPageDirty(page) test_and_set_bit(PG_dirty, &(page)->flags)
-#define ClearPageDirty(page) clear_bit(PG_dirty, &(page)->flags)
-#define __ClearPageDirty(page) __clear_bit(PG_dirty, &(page)->flags)
-#define TestClearPageDirty(page) test_and_clear_bit(PG_dirty, &(page)->flags)
-
-#define PageLRU(page) test_bit(PG_lru, &(page)->flags)
-#define SetPageLRU(page) set_bit(PG_lru, &(page)->flags)
-#define ClearPageLRU(page) clear_bit(PG_lru, &(page)->flags)
-#define __ClearPageLRU(page) __clear_bit(PG_lru, &(page)->flags)
+CLEARPAGEFLAG(Uptodate, uptodate)
-#define PageActive(page) test_bit(PG_active, &(page)->flags)
-#define SetPageActive(page) set_bit(PG_active, &(page)->flags)
-#define ClearPageActive(page) clear_bit(PG_active, &(page)->flags)
-#define __ClearPageActive(page) __clear_bit(PG_active, &(page)->flags)
-
-#define PageSlab(page) test_bit(PG_slab, &(page)->flags)
-#define __SetPageSlab(page) __set_bit(PG_slab, &(page)->flags)
-#define __ClearPageSlab(page) __clear_bit(PG_slab, &(page)->flags)
-
-#ifdef CONFIG_HIGHMEM
-#define PageHighMem(page) is_highmem(page_zone(page))
-#else
-#define PageHighMem(page) 0 /* needed to optimize away at compile time */
-#endif
-
-#define PageChecked(page) test_bit(PG_checked, &(page)->flags)
-#define SetPageChecked(page) set_bit(PG_checked, &(page)->flags)
-#define ClearPageChecked(page) clear_bit(PG_checked, &(page)->flags)
-
-#define PagePinned(page) test_bit(PG_pinned, &(page)->flags)
-#define SetPagePinned(page) set_bit(PG_pinned, &(page)->flags)
-#define ClearPagePinned(page) clear_bit(PG_pinned, &(page)->flags)
+extern void cancel_dirty_page(struct page *page, unsigned int account_size);
-#define PageReserved(page) test_bit(PG_reserved, &(page)->flags)
-#define SetPageReserved(page) set_bit(PG_reserved, &(page)->flags)
-#define ClearPageReserved(page) clear_bit(PG_reserved, &(page)->flags)
-#define __ClearPageReserved(page) __clear_bit(PG_reserved, &(page)->flags)
+int test_clear_page_writeback(struct page *page);
+int test_set_page_writeback(struct page *page);
-#define SetPagePrivate(page) set_bit(PG_private, &(page)->flags)
-#define ClearPagePrivate(page) clear_bit(PG_private, &(page)->flags)
-#define PagePrivate(page) test_bit(PG_private, &(page)->flags)
-#define __SetPagePrivate(page) __set_bit(PG_private, &(page)->flags)
-#define __ClearPagePrivate(page) __clear_bit(PG_private, &(page)->flags)
+static inline void set_page_writeback(struct page *page)
+{
+ test_set_page_writeback(page);
+}
+#ifdef CONFIG_PAGEFLAGS_EXTENDED
/*
- * Only test-and-set exist for PG_writeback. The unconditional operators are
- * risky: they bypass page accounting.
+ * System with lots of page flags available. This allows separate
+ * flags for PageHead() and PageTail() checks of compound pages so that bit
+ * tests can be used in performance sensitive paths. PageCompound is
+ * generally not used in hot code paths.
*/
-#define PageWriteback(page) test_bit(PG_writeback, &(page)->flags)
-#define TestSetPageWriteback(page) test_and_set_bit(PG_writeback, \
- &(page)->flags)
-#define TestClearPageWriteback(page) test_and_clear_bit(PG_writeback, \
- &(page)->flags)
-
-#define PageBuddy(page) test_bit(PG_buddy, &(page)->flags)
-#define __SetPageBuddy(page) __set_bit(PG_buddy, &(page)->flags)
-#define __ClearPageBuddy(page) __clear_bit(PG_buddy, &(page)->flags)
-
-#define PageMappedToDisk(page) test_bit(PG_mappedtodisk, &(page)->flags)
-#define SetPageMappedToDisk(page) set_bit(PG_mappedtodisk, &(page)->flags)
-#define ClearPageMappedToDisk(page) clear_bit(PG_mappedtodisk, &(page)->flags)
-
-#define PageReadahead(page) test_bit(PG_readahead, &(page)->flags)
-#define SetPageReadahead(page) set_bit(PG_readahead, &(page)->flags)
-#define ClearPageReadahead(page) clear_bit(PG_readahead, &(page)->flags)
+__PAGEFLAG(Head, head)
+__PAGEFLAG(Tail, tail)
-#define PageReclaim(page) test_bit(PG_reclaim, &(page)->flags)
-#define SetPageReclaim(page) set_bit(PG_reclaim, &(page)->flags)
-#define ClearPageReclaim(page) clear_bit(PG_reclaim, &(page)->flags)
-#define TestClearPageReclaim(page) test_and_clear_bit(PG_reclaim, &(page)->flags)
+static inline int PageCompound(struct page *page)
+{
+ return page->flags & ((1L << PG_head) | (1L << PG_tail));
-#define PageCompound(page) test_bit(PG_compound, &(page)->flags)
-#define __SetPageCompound(page) __set_bit(PG_compound, &(page)->flags)
-#define __ClearPageCompound(page) __clear_bit(PG_compound, &(page)->flags)
+}
+#else
+/*
+ * Reduce page flag use as much as possible by overlapping
+ * compound page flags with the flags used for page cache pages. Possible
+ * because PageCompound is always set for compound pages and not for
+ * pages on the LRU and/or pagecache.
+ */
+TESTPAGEFLAG(Compound, compound)
+__PAGEFLAG(Head, compound)
/*
* PG_reclaim is used in combination with PG_compound to mark the
- * head and tail of a compound page
+ * head and tail of a compound page. This saves one page flag
+ * but makes it impossible to use compound pages for the page cache.
+ * The PG_reclaim bit would have to be used for reclaim or readahead
+ * if compound pages enter the page cache.
*
* PG_compound & PG_reclaim => Tail page
* PG_compound & ~PG_reclaim => Head page
*/
-
#define PG_head_tail_mask ((1L << PG_compound) | (1L << PG_reclaim))
-#define PageTail(page) (((page)->flags & PG_head_tail_mask) \
- == PG_head_tail_mask)
+static inline int PageTail(struct page *page)
+{
+ return ((page->flags & PG_head_tail_mask) == PG_head_tail_mask);
+}
static inline void __SetPageTail(struct page *page)
{
page->flags &= ~PG_head_tail_mask;
}
-#define PageHead(page) (((page)->flags & PG_head_tail_mask) \
- == (1L << PG_compound))
-#define __SetPageHead(page) __SetPageCompound(page)
-#define __ClearPageHead(page) __ClearPageCompound(page)
+#endif /* !PAGEFLAGS_EXTENDED */
-#ifdef CONFIG_SWAP
-#define PageSwapCache(page) test_bit(PG_swapcache, &(page)->flags)
-#define SetPageSwapCache(page) set_bit(PG_swapcache, &(page)->flags)
-#define ClearPageSwapCache(page) clear_bit(PG_swapcache, &(page)->flags)
-#else
-#define PageSwapCache(page) 0
-#endif
-
-#define PageUncached(page) test_bit(PG_uncached, &(page)->flags)
-#define SetPageUncached(page) set_bit(PG_uncached, &(page)->flags)
-#define ClearPageUncached(page) clear_bit(PG_uncached, &(page)->flags)
-
-struct page; /* forward declaration */
+#define PAGE_FLAGS (1 << PG_lru | 1 << PG_private | 1 << PG_locked | \
+ 1 << PG_buddy | 1 << PG_writeback | \
+ 1 << PG_slab | 1 << PG_swapcache | 1 << PG_active)
-extern void cancel_dirty_page(struct page *page, unsigned int account_size);
+/*
+ * Flags checked in bad_page(). Pages on the free list should not have
+ * these flags set. It they are, there is a problem.
+ */
+#define PAGE_FLAGS_CLEAR_WHEN_BAD (PAGE_FLAGS | 1 << PG_reclaim | 1 << PG_dirty)
-int test_clear_page_writeback(struct page *page);
-int test_set_page_writeback(struct page *page);
+/*
+ * Flags checked when a page is freed. Pages being freed should not have
+ * these flags set. It they are, there is a problem.
+ */
+#define PAGE_FLAGS_CHECK_AT_FREE (PAGE_FLAGS | 1 << PG_reserved)
-static inline void set_page_writeback(struct page *page)
-{
- test_set_page_writeback(page);
-}
+/*
+ * Flags checked when a page is prepped for return by the page allocator.
+ * Pages being prepped should not have these flags set. It they are, there
+ * is a problem.
+ */
+#define PAGE_FLAGS_CHECK_AT_PREP (PAGE_FLAGS | 1 << PG_reserved | 1 << PG_dirty)
#endif /* !__GENERATING_BOUNDS_H */
#endif /* PAGE_FLAGS_H */
git.openpandora.org / pandora-kernel.git / blobdiff