Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff
[linux-2.6.git] / include / linux / page-flags.h
index 39ab8c6..d276a4e 100644 (file)
 
 /*
  * 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
 
@@ -98,32 +122,40 @@ struct page_state {
        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 */
@@ -135,32 +167,56 @@ struct page_state {
 };
 
 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
@@ -195,27 +251,25 @@ extern void __mod_page_state(unsigned offset, unsigned long delta);
 #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
@@ -277,6 +331,10 @@ extern void __mod_page_state(unsigned offset, unsigned long delta);
 #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)
@@ -286,13 +344,9 @@ extern void __mod_page_state(unsigned offset, unsigned long delta);
 #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)