The shrink_zone() logic can, under some circumstances, cause far too many
pages to be reclaimed. Say, we're scanning at high priority and suddenly hit
a large number of reclaimable pages on the LRU.
Change things so we bale out when SWAP_CLUSTER_MAX pages have been reclaimed.
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/mm/vmscan.c | 8 ++++++++
1 files changed, 8 insertions(+)
diff -puN mm/vmscan.c~vmscan-dont-reclaim-too-many-pages mm/vmscan.c
--- 25/mm/vmscan.c~vmscan-dont-reclaim-too-many-pages 2004-06-16 00:47:52.002318472 -0700
+++ 25-akpm/mm/vmscan.c 2004-06-16 00:50:18.338072056 -0700
@@ -62,6 +62,9 @@ struct scan_control {
unsigned long nr_mapped; /* From page_state */
+ /* How many pages shrink_cache() should reclaim */
+ int nr_to_reclaim;
+
/* Ask shrink_caches, or shrink_zone to scan at this priority */
unsigned int priority;
@@ -586,6 +589,7 @@ static void shrink_cache(struct zone *zo
if (current_is_kswapd())
mod_page_state(kswapd_steal, nr_freed);
mod_page_state_zone(zone, pgsteal, nr_freed);
+ sc->nr_to_reclaim -= nr_freed;
spin_lock_irq(&zone->lru_lock);
/*
@@ -815,6 +819,8 @@ shrink_zone(struct zone *zone, struct sc
else
nr_inactive = 0;
+ sc->nr_to_reclaim = SWAP_CLUSTER_MAX;
+
while (nr_active || nr_inactive) {
if (nr_active) {
sc->nr_to_scan = min(nr_active,
@@ -828,6 +834,8 @@ shrink_zone(struct zone *zone, struct sc
(unsigned long)SWAP_CLUSTER_MAX);
nr_inactive -= sc->nr_to_scan;
shrink_cache(zone, sc);
+ if (sc->nr_to_reclaim <= 0)
+ break;
}
}
}
_