[PATCH 2/3] Refactor zone_reclaim

Balbir Singh
2010-11-30T10:16:06Z

Refactor zone_reclaim, move reusable functionality outside
of zone_reclaim. Make zone_reclaim_unmapped_pages modular

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
---
mm/vmscan.c | 35 +++++++++++++++++++++++------------
1 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 325443a..0ac444f 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2719,6 +2719,27 @@ static long zone_pagecache_reclaimable(struct zone *zone)
}

/*
+ * Helper function to reclaim unmapped pages, we might add something
+ * similar to this for slab cache as well. Currently this function
+ * is shared with __zone_reclaim()
+ */
+static inline void
+zone_reclaim_unmapped_pages(struct zone *zone, struct scan_control *sc,
+ unsigned long nr_pages)
+{
+ int priority;
+ /*
+ * Free memory by calling shrink zone with increasing
+ * priorities until we have enough memory freed.
+ */
+ priority = ZONE_RECLAIM_PRIORITY;
+ do {
+ shrink_zone(priority, zone, sc);
+ priority--;
+ } while (priority >= 0 && sc->nr_reclaimed < nr_pages);
+}
+
+/*
* Try to free up some pages from this zone through reclaim.
*/
static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
@@ -2727,7 +2748,6 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
const unsigned long nr_pages = 1 << order;
struct task_struct *p = current;
struct reclaim_state reclaim_state;
- int priority;
struct scan_control sc = {
.may_writepage = !!(zone_reclaim_mode & RECLAIM_WRITE),
.may_unmap = !!(zone_reclaim_mode & RECLAIM_SWAP),
@@ -2751,17 +2771,8 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
reclaim_state.reclaimed_slab = 0;
p->reclaim_state = &reclaim_state;

- if (zone_pagecache_reclaimable(zone) > zone->min_unmapped_pages) {
- /*
- * Free memory by calling shrink zone with increasing
- * priorities until we have enough memory freed.
- */
- priority = ZONE_RECLAIM_PRIORITY;
- do {
- shrink_zone(priority, zone, &sc);
- priority--;
- } while (priority >= 0 && sc.nr_reclaimed < nr_pages);
- }
+ if (zone_pagecache_reclaimable(zone) > zone->min_unmapped_pages)
+ zone_reclaim_unmapped_pages(zone, &sc, nr_pages);

nr_slab_pages0 = zone_page_state(zone, NR_SLAB_RECLAIMABLE);
if (nr_slab_pages0 > zone->min_slab_pages) {