'slab_reclaimable' and 'nr_pages' are unsigned. so, subtraction is
unsafe.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Acked-by: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmscan.c | 14 +++++++-------
1 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 9c7e57c..8715da1 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2588,7 +2588,7 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
.swappiness = vm_swappiness,
.order = order,
};
- unsigned long slab_reclaimable;
+ unsigned long n, m;
disable_swap_token();
cond_resched();
@@ -2615,8 +2615,8 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
} while (priority >= 0 && sc.nr_reclaimed < nr_pages);
}
- slab_reclaimable = zone_page_state(zone, NR_SLAB_RECLAIMABLE);
- if (slab_reclaimable > zone->min_slab_pages) {
+ n = zone_page_state(zone, NR_SLAB_RECLAIMABLE);
+ if (n > zone->min_slab_pages) {
/*
* shrink_slab() does not currently allow us to determine how
* many pages were freed in this zone. So we take the current
@@ -2628,16 +2628,16 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
* take a long time.
*/
while (shrink_slab(sc.nr_scanned, gfp_mask, order) &&
- zone_page_state(zone, NR_SLAB_RECLAIMABLE) >
- slab_reclaimable - nr_pages)
+ (zone_page_state(zone, NR_SLAB_RECLAIMABLE) + nr_pages > n))
;
/*
* Update nr_reclaimed by the number of slab pages we
* reclaimed from this zone.
*/
- sc.nr_reclaimed += slab_reclaimable -
- zone_page_state(zone, NR_SLAB_RECLAIMABLE);
+ m = zone_page_state(zone, NR_SLAB_RECLAIMABLE);
+ if (m < n)
+ sc.nr_reclaimed += n - m;
}
p->reclaim_state = NULL;
--
1.6.5.2
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