Re: kswapd in tight loop 2.6.9-rc3-bk-recent

[Nick Piggin]

Andrew Morton wrote:

> Chris Wright <chrisw@xxxxxxxx> wrote:
>
> > (whereas I could get the mainline code, and the
> > one-liner to spin right off).  
>
> How?  (up to and including .config please).

Ah, free_pages <= pages_high, ie. 0 <= 0, which is true;
commence spinning.

How's this go?




Signed-off-by: Nick Piggin <nickpiggin@xxxxxxxxxxxx>


---

 linux-2.6-npiggin/mm/vmscan.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff -puN mm/vmscan.c~vm-fix-empty-zones mm/vmscan.c
--- linux-2.6/mm/vmscan.c~vm-fix-empty-zones	2004-10-08 12:44:14.000000000 +1000
+++ linux-2.6-npiggin/mm/vmscan.c	2004-10-08 12:44:48.000000000 +1000
@@ -1003,7 +1003,7 @@ static int balance_pgdat(pg_data_t *pgda
 						priority != DEF_PRIORITY)
 					continue;
 
-				if (zone->free_pages <= zone->pages_high) {
+				if (zone->free_pages < zone->pages_high) {
 					end_zone = i;
 					goto scan;
 				}
@@ -1035,7 +1035,7 @@ scan:
 				continue;
 
 			if (nr_pages == 0) {	/* Not software suspend */
-				if (zone->free_pages <= zone->pages_high)
+				if (zone->free_pages < zone->pages_high)
 					all_zones_ok = 0;
 			}
 			zone->temp_priority = priority;
@@ -1142,7 +1142,7 @@ static int kswapd(void *p)
  */
 void wakeup_kswapd(struct zone *zone)
 {
-	if (zone->free_pages > zone->pages_low)
+	if (zone->free_pages >= zone->pages_low)
 		return;
 	if (!waitqueue_active(&zone->zone_pgdat->kswapd_wait))
 		return;

_