:Hi,
:
:
:Should restore hysteresis to the idle zero logic. The simplest way to do
:this was to add the zero_state set to vm_page_zero_check().
:
:-- vs
Hmm. That still doesn't look quite right. I think the LO and the HI
are reversed. How about this instead?
-Matt
Matthew Dillon
<dillon@backplane.com>
diff --git a/sys/vm/vm_zeroidle.c b/sys/vm/vm_zeroidle.c
index 276cc3a..02a7515 100644
--- a/sys/vm/vm_zeroidle.c
+++ b/sys/vm/vm_zeroidle.c
@@ -35,8 +35,6 @@
* from: @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91
* Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
* from FreeBSD: .../i386/vm_machdep.c,v 1.165 2001/07/04 23:27:04 dillon
- *
- * $Id: vm_zeroidle.c,v 1.3 2010/05/12 04:50:45 sv5679 Exp $
*/
#include <sys/param.h>
@@ -67,7 +65,6 @@
/* Maximum number of pages per second to zero */
#define NPAGES_RUN (20000)
-
static int idlezero_enable = 0;
TUNABLE_INT("vm.idlezero_enable", &idlezero_enable);
SYSCTL_INT(_vm, OID_AUTO, idlezero_enable, CTLFLAG_RW, &idlezero_enable, 0,
@@ -99,17 +96,30 @@ static int zero_state;
* Otherwise we might get 'flutter' during disk I/O / IPC or
* fast sleeps. We also do not want to be continuously zeroing
* pages because doing so may flush our L1 and L2 caches too much.
+ *
+ * Returns non-zero if pages should be zerod.
*/
static int
vm_page_zero_check(void)
{
if (idlezero_enable == 0)
return (0);
- if (zero_state && vm_page_zero_count >= ZIDLE_LO(vmstats.v_free_count))
- return (0);
- if (vm_page_zero_count >= ZIDLE_HI(vmstats.v_free_count))
- return (0);
- return (1);
+ if (zero_state == 0) {
+ /*
+ * Wait for the count to fall to LO before starting
+ * to zero pages.
+ */
+ if (vm_page_zero_count <= ZIDLE_LO(vmstats.v_free_count))
+ zero_state = 1;
+ } else {
+ /*
+ * Once we are zeroing pages wait for the count to
+ * increase to HI before we stop zeroing pages.
+ */
+ if (vm_page_zero_count >= ZIDLE_HI(vmstats.v_free_count))
+ zero_state = 0;
+ }
+ return (zero_state);
}
static void