diff options
| author | Niklas Hallqvist <niklas@cvs.openbsd.org> | 1996-08-13 22:22:18 +0000 |
|---|---|---|
| committer | Niklas Hallqvist <niklas@cvs.openbsd.org> | 1996-08-13 22:22:18 +0000 |
| commit | 8822cb3d8120d02c5cf02f49a2b98fca171079f5 (patch) | |
| tree | 328200e23930c55ceeb692510ae1589283ac07c7 | |
| parent | 673b0fb7cea4ecda9843ee61f5688122b8525169 (diff) | |
Document PG_CLEANs role in collapse
| -rw-r--r-- | sys/vm/vm_page.h | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/sys/vm/vm_page.h b/sys/vm/vm_page.h index 584d7365f58..14a529cf9fe 100644 --- a/sys/vm/vm_page.h +++ b/sys/vm/vm_page.h @@ -1,4 +1,4 @@ -/* $OpenBSD: vm_page.h,v 1.2 1996/08/02 00:06:03 niklas Exp $ */ +/* $OpenBSD: vm_page.h,v 1.3 1996/08/13 22:22:17 niklas Exp $ */ /* $NetBSD: vm_page.h,v 1.18 1995/03/26 20:39:13 jtc Exp $ */ /* @@ -121,8 +121,17 @@ struct vm_page { */ #define PG_INACTIVE 0x0001 /* page is in inactive list (P) */ #define PG_ACTIVE 0x0002 /* page is in active list (P) */ -#define PG_LAUNDRY 0x0004 /* page is being cleaned now (P)*/ -#define PG_CLEAN 0x0008 /* page has not been modified */ +#define PG_LAUNDRY 0x0004 /* page is being cleaned now (P) */ +#define PG_CLEAN 0x0008 /* page has not been modified + There exists a case where this bit + will be cleared, although the page + is not physically dirty, which is + when a collapse operation moves + pages between two different pagers. + The bit is then used as a marker + for the pageout daemon to know it + should be paged out into the target + pager. */ #define PG_BUSY 0x0010 /* page is in transit (O) */ #define PG_WANTED 0x0020 /* someone is waiting for page (O) */ #define PG_TABLED 0x0040 /* page is in VP table (O) */ |