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authorDmitry Torokhov <dtor_core@ameritech.net>2006-04-29 01:11:23 -0400
committerDmitry Torokhov <dtor_core@ameritech.net>2006-04-29 01:11:23 -0400
commit7b7e394185014e0f3bd8989cac937003f20ef9ce (patch)
tree3beda5f979bba0aa9822534e239cf1b45f3be69c /include/linux/page-flags.h
parentddc5d3414593e4d7ad7fbd33e7f7517fcc234544 (diff)
parent693f7d362055261882659475d2ef022e32edbff1 (diff)
downloadop-kernel-dev-7b7e394185014e0f3bd8989cac937003f20ef9ce.zip
op-kernel-dev-7b7e394185014e0f3bd8989cac937003f20ef9ce.tar.gz
Merge rsync://rsync.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'include/linux/page-flags.h')
-rw-r--r--include/linux/page-flags.h24
1 files changed, 21 insertions, 3 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 9ea629c..d276a4e 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -48,8 +48,20 @@
/*
* 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
@@ -74,7 +86,9 @@
#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_uncached 19 /* Page has been mapped as uncached */
+#define PG_buddy 19 /* Page is free, on buddy lists */
+
+#define PG_uncached 20 /* Page has been mapped as uncached */
/*
* Global page accounting. One instance per CPU. Only unsigned longs are
@@ -317,6 +331,10 @@ extern void __mod_page_state_offset(unsigned long 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)
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