/*
* Don't use the *_dontuse flags. Use the macros. Otherwise you'll break
- * locked- and dirty-page accounting. The top eight bits of page->flags are
- * used for page->zone, so putting flag bits there doesn't work.
+ * locked- and dirty-page accounting.
+ *
+ * The page flags field is split into two parts, the main flags area
+ * which extends from the low bits upwards, and the fields area which
+ * extends from the high bits downwards.
+ *
+ * | FIELD | ... | FLAGS |
+ * N-1 ^ 0
+ * (N-FLAGS_RESERVED)
+ *
+ * The fields area is reserved for fields mapping zone, node and SPARSEMEM
+ * section. The boundry between these two areas is defined by
+ * FLAGS_RESERVED which defines the width of the fields section
+ * (see linux/mmzone.h). New flags must _not_ overlap with this area.
*/
#define PG_locked 0 /* Page is locked. Don't touch. */
#define PG_error 1
#define PG_active 6
#define PG_slab 7 /* slab debug (Suparna wants this) */
-#define PG_highmem 8
-#define PG_checked 9 /* kill me in 2.5.<early>. */
-#define PG_arch_1 10
-#define PG_reserved 11
+#define PG_checked 8 /* kill me in 2.5.<early>. */
+#define PG_arch_1 9
+#define PG_reserved 10
+#define PG_private 11 /* Has something at ->private */
-#define PG_private 12 /* Has something at ->private */
-#define PG_writeback 13 /* Page is under writeback */
-#define PG_nosave 14 /* Used for system suspend/resume */
-#define PG_compound 15 /* Part of a compound page */
+#define PG_writeback 12 /* Page is under writeback */
+#define PG_nosave 13 /* Used for system suspend/resume */
+#define PG_compound 14 /* Part of a compound page */
+#define PG_swapcache 15 /* Swap page: swp_entry_t in private */
+
+#define PG_mappedtodisk 16 /* Has blocks allocated on-disk */
+#define PG_reclaim 17 /* To be reclaimed asap */
+#define PG_nosave_free 18 /* Free, should not be written */
+#define PG_buddy 19 /* Page is free, on buddy lists */
-#define PG_swapcache 16 /* Swap page: swp_entry_t in private */
-#define PG_mappedtodisk 17 /* Has blocks allocated on-disk */
-#define PG_reclaim 18 /* To be reclaimed asap */
-#define PG_nosave_free 19 /* Free, should not be written */
#define PG_uncached 20 /* Page has been mapped as uncached */
/*
* Global page accounting. One instance per CPU. Only unsigned longs are
* allowed.
+ *
+ * - Fields can be modified with xxx_page_state and xxx_page_state_zone at
+ * any time safely (which protects the instance from modification by
+ * interrupt.
+ * - The __xxx_page_state variants can be used safely when interrupts are
+ * disabled.
+ * - The __xxx_page_state variants can be used if the field is only
+ * modified from process context and protected from preemption, or only
+ * modified from interrupt context. In this case, the field should be
+ * commented here.
*/
struct page_state {
unsigned long nr_dirty; /* Dirty writeable pages */
unsigned long nr_writeback; /* Pages under writeback */
unsigned long nr_unstable; /* NFS unstable pages */
unsigned long nr_page_table_pages;/* Pages used for pagetables */
- unsigned long nr_mapped; /* mapped into pagetables */
+ unsigned long nr_mapped; /* mapped into pagetables.
+ * only modified from process context */
unsigned long nr_slab; /* In slab */
#define GET_PAGE_STATE_LAST nr_slab
unsigned long pgpgout; /* Disk writes */
unsigned long pswpin; /* swap reads */
unsigned long pswpout; /* swap writes */
- unsigned long pgalloc_high; /* page allocations */
+ unsigned long pgalloc_high; /* page allocations */
unsigned long pgalloc_normal;
+ unsigned long pgalloc_dma32;
unsigned long pgalloc_dma;
+
unsigned long pgfree; /* page freeings */
unsigned long pgactivate; /* pages moved inactive->active */
unsigned long pgdeactivate; /* pages moved active->inactive */
unsigned long pgfault; /* faults (major+minor) */
unsigned long pgmajfault; /* faults (major only) */
+
unsigned long pgrefill_high; /* inspected in refill_inactive_zone */
unsigned long pgrefill_normal;
+ unsigned long pgrefill_dma32;
unsigned long pgrefill_dma;
unsigned long pgsteal_high; /* total highmem pages reclaimed */
unsigned long pgsteal_normal;
+ unsigned long pgsteal_dma32;
unsigned long pgsteal_dma;
+
unsigned long pgscan_kswapd_high;/* total highmem pages scanned */
unsigned long pgscan_kswapd_normal;
-
+ unsigned long pgscan_kswapd_dma32;
unsigned long pgscan_kswapd_dma;
+
unsigned long pgscan_direct_high;/* total highmem pages scanned */
unsigned long pgscan_direct_normal;
+ unsigned long pgscan_direct_dma32;
unsigned long pgscan_direct_dma;
- unsigned long pginodesteal; /* pages reclaimed via inode freeing */
+ unsigned long pginodesteal; /* pages reclaimed via inode freeing */
unsigned long slabs_scanned; /* slab objects scanned */
unsigned long kswapd_steal; /* pages reclaimed by kswapd */
unsigned long kswapd_inodesteal;/* reclaimed via kswapd inode freeing */
};
extern void get_page_state(struct page_state *ret);
+extern void get_page_state_node(struct page_state *ret, int node);
extern void get_full_page_state(struct page_state *ret);
-extern unsigned long __read_page_state(unsigned offset);
-extern void __mod_page_state(unsigned offset, unsigned long delta);
+extern unsigned long read_page_state_offset(unsigned long offset);
+extern void mod_page_state_offset(unsigned long offset, unsigned long delta);
+extern void __mod_page_state_offset(unsigned long offset, unsigned long delta);
#define read_page_state(member) \
- __read_page_state(offsetof(struct page_state, member))
+ read_page_state_offset(offsetof(struct page_state, member))
#define mod_page_state(member, delta) \
- __mod_page_state(offsetof(struct page_state, member), (delta))
-
-#define inc_page_state(member) mod_page_state(member, 1UL)
-#define dec_page_state(member) mod_page_state(member, 0UL - 1)
-#define add_page_state(member,delta) mod_page_state(member, (delta))
-#define sub_page_state(member,delta) mod_page_state(member, 0UL - (delta))
-
-#define mod_page_state_zone(zone, member, delta) \
- do { \
- unsigned offset; \
- if (is_highmem(zone)) \
- offset = offsetof(struct page_state, member##_high); \
- else if (is_normal(zone)) \
- offset = offsetof(struct page_state, member##_normal); \
- else \
- offset = offsetof(struct page_state, member##_dma); \
- __mod_page_state(offset, (delta)); \
- } while (0)
+ mod_page_state_offset(offsetof(struct page_state, member), (delta))
+
+#define __mod_page_state(member, delta) \
+ __mod_page_state_offset(offsetof(struct page_state, member), (delta))
+
+#define inc_page_state(member) mod_page_state(member, 1UL)
+#define dec_page_state(member) mod_page_state(member, 0UL - 1)
+#define add_page_state(member,delta) mod_page_state(member, (delta))
+#define sub_page_state(member,delta) mod_page_state(member, 0UL - (delta))
+
+#define __inc_page_state(member) __mod_page_state(member, 1UL)
+#define __dec_page_state(member) __mod_page_state(member, 0UL - 1)
+#define __add_page_state(member,delta) __mod_page_state(member, (delta))
+#define __sub_page_state(member,delta) __mod_page_state(member, 0UL - (delta))
+
+#define page_state(member) (*__page_state(offsetof(struct page_state, member)))
+
+#define state_zone_offset(zone, member) \
+({ \
+ unsigned offset; \
+ if (is_highmem(zone)) \
+ offset = offsetof(struct page_state, member##_high); \
+ else if (is_normal(zone)) \
+ offset = offsetof(struct page_state, member##_normal); \
+ else if (is_dma32(zone)) \
+ offset = offsetof(struct page_state, member##_dma32); \
+ else \
+ offset = offsetof(struct page_state, member##_dma); \
+ offset; \
+})
+
+#define __mod_page_state_zone(zone, member, delta) \
+ do { \
+ __mod_page_state_offset(state_zone_offset(zone, member), (delta)); \
+ } while (0)
+
+#define mod_page_state_zone(zone, member, delta) \
+ do { \
+ mod_page_state_offset(state_zone_offset(zone, member), (delta)); \
+ } while (0)
/*
* Manipulation of page state 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 SetPageLRU(page) set_bit(PG_lru, &(page)->flags)
#define PageLRU(page) test_bit(PG_lru, &(page)->flags)
-#define TestSetPageLRU(page) test_and_set_bit(PG_lru, &(page)->flags)
-#define TestClearPageLRU(page) test_and_clear_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)
#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 TestClearPageActive(page) test_and_clear_bit(PG_active, &(page)->flags)
-#define TestSetPageActive(page) test_and_set_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)
-#define TestClearPageSlab(page) test_and_clear_bit(PG_slab, &(page)->flags)
-#define TestSetPageSlab(page) test_and_set_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) test_bit(PG_highmem, &(page)->flags)
+#define PageHighMem(page) is_highmem(page_zone(page))
#else
#define PageHighMem(page) 0 /* needed to optimize away at compile time */
#endif
#define SetPageNosaveFree(page) set_bit(PG_nosave_free, &(page)->flags)
#define ClearPageNosaveFree(page) clear_bit(PG_nosave_free, &(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 ClearPageReclaim(page) clear_bit(PG_reclaim, &(page)->flags)
#define TestClearPageReclaim(page) test_and_clear_bit(PG_reclaim, &(page)->flags)
-#ifdef CONFIG_HUGETLB_PAGE
#define PageCompound(page) test_bit(PG_compound, &(page)->flags)
-#else
-#define PageCompound(page) 0
-#endif
-#define SetPageCompound(page) set_bit(PG_compound, &(page)->flags)
-#define ClearPageCompound(page) clear_bit(PG_compound, &(page)->flags)
+#define __SetPageCompound(page) __set_bit(PG_compound, &(page)->flags)
+#define __ClearPageCompound(page) __clear_bit(PG_compound, &(page)->flags)
#ifdef CONFIG_SWAP
#define PageSwapCache(page) test_bit(PG_swapcache, &(page)->flags)