[PATCH 08/10] mm: Modify vmscan

From: Ankita Garg
Date: Fri May 27 2011 - 08:33:16 EST

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Modify vmscan to take into account the changed node-zone hierarchy.

Signed-off-by: Ankita Garg <ankita@xxxxxxxxxx>
---
mm/vmscan.c | 284 ++++++++++++++++++++++++++++++++---------------------------
1 files changed, 153 insertions(+), 131 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 8bfd450..2e11974 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2235,10 +2235,16 @@ static bool pgdat_balanced(pg_data_t *pgdat, unsigned long balanced_pages,
int classzone_idx)
{
unsigned long present_pages = 0;
- int i;
-
- for (i = 0; i <= classzone_idx; i++)
- present_pages += pgdat->node_zones[i].present_pages;
+ int i, p;
+
+ for (i = 0; i <= classzone_idx; i++) {
+ for_each_mem_region_in_nid(p, pgdat->node_id) {
+ mem_region_t *mem_region = &pgdat->mem_regions[p];
+ struct zone *zone = mem_region->zones + i;
+
+ present_pages += zone->present_pages;
+ }
+ }

return balanced_pages > (present_pages >> 2);
}
@@ -2247,7 +2253,7 @@ static bool pgdat_balanced(pg_data_t *pgdat, unsigned long balanced_pages,
static bool sleeping_prematurely(pg_data_t *pgdat, int order, long remaining,
int classzone_idx)
{
- int i;
+ int i, j;
unsigned long balanced = 0;
bool all_zones_ok = true;

@@ -2257,29 +2263,31 @@ static bool sleeping_prematurely(pg_data_t *pgdat, int order, long remaining,

/* Check the watermark levels */
for (i = 0; i < pgdat->nr_zones; i++) {
- struct zone *zone = pgdat->node_zones + i;
+ for_each_mem_region_in_nid(j, pgdat->node_id) {
+ mem_region_t *mem_region = &pgdat->mem_regions[j];
+ struct zone *zone = mem_region->zones + i;

- if (!populated_zone(zone))
- continue;
+ if (!populated_zone(zone))
+ continue;

- /*
- * balance_pgdat() skips over all_unreclaimable after
- * DEF_PRIORITY. Effectively, it considers them balanced so
- * they must be considered balanced here as well if kswapd
- * is to sleep
- */
- if (zone->all_unreclaimable) {
- balanced += zone->present_pages;
- continue;
- }
+ /*
+ * balance_pgdat() skips over all_unreclaimable after
+ * DEF_PRIORITY. Effectively, it considers them balanced so
+ * they must be considered balanced here as well if kswapd
+ * is to sleep
+ */
+ if (zone->all_unreclaimable) {
+ balanced += zone->present_pages;
+ continue;
+ }

- if (!zone_watermark_ok_safe(zone, order, high_wmark_pages(zone),
- classzone_idx, 0))
- all_zones_ok = false;
- else
- balanced += zone->present_pages;
+ if (!zone_watermark_ok_safe(zone, order, high_wmark_pages(zone),
+ classzone_idx, 0))
+ all_zones_ok = false;
+ else
+ balanced += zone->present_pages;
+ }
}
-
/*
* For high-order requests, the balanced zones must contain at least
* 25% of the nodes pages for kswapd to sleep. For order-0, all zones
@@ -2318,7 +2326,7 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
int all_zones_ok;
unsigned long balanced;
int priority;
- int i;
+ int i, p;
int end_zone = 0; /* Inclusive. 0 = ZONE_DMA */
unsigned long total_scanned;
struct reclaim_state *reclaim_state = current->reclaim_state;
@@ -2357,36 +2365,42 @@ loop_again:
* zone which needs scanning
*/
for (i = pgdat->nr_zones - 1; i >= 0; i--) {
- struct zone *zone = pgdat->node_zones + i;
+ for_each_mem_region_in_nid(p, pgdat->node_id) {
+ mem_region_t *mem_region = &pgdat->mem_regions[p];
+ struct zone *zone = mem_region->zones + i;

- if (!populated_zone(zone))
- continue;
+ if (!populated_zone(zone))
+ continue;

- if (zone->all_unreclaimable && priority != DEF_PRIORITY)
- continue;
+ if (zone->all_unreclaimable && priority != DEF_PRIORITY)
+ continue;

- /*
- * Do some background aging of the anon list, to give
- * pages a chance to be referenced before reclaiming.
- */
- if (inactive_anon_is_low(zone, &sc))
- shrink_active_list(SWAP_CLUSTER_MAX, zone,
- &sc, priority, 0);
-
- if (!zone_watermark_ok_safe(zone, order,
- high_wmark_pages(zone), 0, 0)) {
- end_zone = i;
- *classzone_idx = i;
- break;
+ /*
+ * Do some background aging of the anon list, to give
+ * pages a chance to be referenced before reclaiming.
+ */
+ if (inactive_anon_is_low(zone, &sc))
+ shrink_active_list(SWAP_CLUSTER_MAX, zone,
+ &sc, priority, 0);
+
+ if (!zone_watermark_ok_safe(zone, order,
+ high_wmark_pages(zone), 0, 0)) {
+ end_zone = i;
+ *classzone_idx = i;
+ break;
+ }
}
}
if (i < 0)
goto out;

for (i = 0; i <= end_zone; i++) {
- struct zone *zone = pgdat->node_zones + i;
+ for_each_mem_region_in_nid(p, pgdat->node_id) {
+ mem_region_t *mem_region = &pgdat->mem_regions[p];
+ struct zone *zone = mem_region->zones + i;

- lru_pages += zone_reclaimable_pages(zone);
+ lru_pages += zone_reclaimable_pages(zone);
+ }
}

/*
@@ -2399,84 +2413,86 @@ loop_again:
* cause too much scanning of the lower zones.
*/
for (i = 0; i <= end_zone; i++) {
- struct zone *zone = pgdat->node_zones + i;
- int nr_slab;
- unsigned long balance_gap;
-
- if (!populated_zone(zone))
- continue;
+ for_each_mem_region_in_nid(p, pgdat->node_id) {
+ mem_region_t *mem_region = &pgdat->mem_regions[p];
+ struct zone *zone = mem_region->zones + i;
+ int nr_slab;
+ unsigned long balance_gap;

- if (zone->all_unreclaimable && priority != DEF_PRIORITY)
- continue;
+ if (!populated_zone(zone))
+ continue;

- sc.nr_scanned = 0;
+ if (zone->all_unreclaimable && priority != DEF_PRIORITY)
+ continue;

- /*
- * Call soft limit reclaim before calling shrink_zone.
- * For now we ignore the return value
- */
- mem_cgroup_soft_limit_reclaim(zone, order, sc.gfp_mask);
+ sc.nr_scanned = 0;

- /*
- * We put equal pressure on every zone, unless
- * one zone has way too many pages free
- * already. The "too many pages" is defined
- * as the high wmark plus a "gap" where the
- * gap is either the low watermark or 1%
- * of the zone, whichever is smaller.
- */
- balance_gap = min(low_wmark_pages(zone),
- (zone->present_pages +
- KSWAPD_ZONE_BALANCE_GAP_RATIO-1) /
- KSWAPD_ZONE_BALANCE_GAP_RATIO);
- if (!zone_watermark_ok_safe(zone, order,
- high_wmark_pages(zone) + balance_gap,
- end_zone, 0))
- shrink_zone(priority, zone, &sc);
- reclaim_state->reclaimed_slab = 0;
- nr_slab = shrink_slab(sc.nr_scanned, GFP_KERNEL,
- lru_pages);
- sc.nr_reclaimed += reclaim_state->reclaimed_slab;
- total_scanned += sc.nr_scanned;
-
- if (zone->all_unreclaimable)
- continue;
- if (nr_slab == 0 &&
- !zone_reclaimable(zone))
- zone->all_unreclaimable = 1;
- /*
- * If we've done a decent amount of scanning and
- * the reclaim ratio is low, start doing writepage
- * even in laptop mode
- */
- if (total_scanned > SWAP_CLUSTER_MAX * 2 &&
- total_scanned > sc.nr_reclaimed + sc.nr_reclaimed / 2)
- sc.may_writepage = 1;
+ /*
+ * Call soft limit reclaim before calling shrink_zone.
+ * For now we ignore the return value
+ */
+ mem_cgroup_soft_limit_reclaim(zone, order, sc.gfp_mask);

- if (!zone_watermark_ok_safe(zone, order,
- high_wmark_pages(zone), end_zone, 0)) {
- all_zones_ok = 0;
/*
- * We are still under min water mark. This
- * means that we have a GFP_ATOMIC allocation
- * failure risk. Hurry up!
+ * We put equal pressure on every zone, unless
+ * one zone has way too many pages free
+ * already. The "too many pages" is defined
+ * as the high wmark plus a "gap" where the
+ * gap is either the low watermark or 1%
+ * of the zone, whichever is smaller.
*/
+ balance_gap = min(low_wmark_pages(zone),
+ (zone->present_pages +
+ KSWAPD_ZONE_BALANCE_GAP_RATIO-1) /
+ KSWAPD_ZONE_BALANCE_GAP_RATIO);
if (!zone_watermark_ok_safe(zone, order,
- min_wmark_pages(zone), end_zone, 0))
- has_under_min_watermark_zone = 1;
- } else {
+ high_wmark_pages(zone) + balance_gap,
+ end_zone, 0))
+ shrink_zone(priority, zone, &sc);
+ reclaim_state->reclaimed_slab = 0;
+ nr_slab = shrink_slab(sc.nr_scanned, GFP_KERNEL,
+ lru_pages);
+ sc.nr_reclaimed += reclaim_state->reclaimed_slab;
+ total_scanned += sc.nr_scanned;
+
+ if (zone->all_unreclaimable)
+ continue;
+ if (nr_slab == 0 &&
+ !zone_reclaimable(zone))
+ zone->all_unreclaimable = 1;
/*
- * If a zone reaches its high watermark,
- * consider it to be no longer congested. It's
- * possible there are dirty pages backed by
- * congested BDIs but as pressure is relieved,
- * spectulatively avoid congestion waits
+ * If we've done a decent amount of scanning and
+ * the reclaim ratio is low, start doing writepage
+ * even in laptop mode
*/
- zone_clear_flag(zone, ZONE_CONGESTED);
- if (i <= *classzone_idx)
- balanced += zone->present_pages;
- }
+ if (total_scanned > SWAP_CLUSTER_MAX * 2 &&
+ total_scanned > sc.nr_reclaimed + sc.nr_reclaimed / 2)
+ sc.may_writepage = 1;

+ if (!zone_watermark_ok_safe(zone, order,
+ high_wmark_pages(zone), end_zone, 0)) {
+ all_zones_ok = 0;
+ /*
+ * We are still under min water mark. This
+ * means that we have a GFP_ATOMIC allocation
+ * failure risk. Hurry up!
+ */
+ if (!zone_watermark_ok_safe(zone, order,
+ min_wmark_pages(zone), end_zone, 0))
+ has_under_min_watermark_zone = 1;
+ } else {
+ /*
+ * If a zone reaches its high watermark,
+ * consider it to be no longer congested. It's
+ * possible there are dirty pages backed by
+ * congested BDIs but as pressure is relieved,
+ * spectulatively avoid congestion waits
+ */
+ zone_clear_flag(zone, ZONE_CONGESTED);
+ if (i <= *classzone_idx)
+ balanced += zone->present_pages;
+ }
+ }
}
if (all_zones_ok || (order && pgdat_balanced(pgdat, balanced, *classzone_idx)))
break; /* kswapd: all done */
@@ -2542,23 +2558,26 @@ out:
*/
if (order) {
for (i = 0; i <= end_zone; i++) {
- struct zone *zone = pgdat->node_zones + i;
+ for_each_mem_region_in_nid(p, pgdat->node_id) {
+ mem_region_t *mem_region = &pgdat->mem_regions[p];
+ struct zone *zone = mem_region->zones + i;

- if (!populated_zone(zone))
- continue;
+ if (!populated_zone(zone))
+ continue;

- if (zone->all_unreclaimable && priority != DEF_PRIORITY)
- continue;
+ if (zone->all_unreclaimable && priority != DEF_PRIORITY)
+ continue;

- /* Confirm the zone is balanced for order-0 */
- if (!zone_watermark_ok(zone, 0,
- high_wmark_pages(zone), 0, 0)) {
- order = sc.order = 0;
- goto loop_again;
- }
+ /* Confirm the zone is balanced for order-0 */
+ if (!zone_watermark_ok(zone, 0,
+ high_wmark_pages(zone), 0, 0)) {
+ order = sc.order = 0;
+ goto loop_again;
+ }

- /* If balanced, clear the congested flag */
- zone_clear_flag(zone, ZONE_CONGESTED);
+ /* If balanced, clear the congested flag */
+ zone_clear_flag(zone, ZONE_CONGESTED);
+ }
}
}

@@ -3304,18 +3323,21 @@ static ssize_t write_scan_unevictable_node(struct sys_device *dev,
struct sysdev_attribute *attr,
const char *buf, size_t count)
{
- struct zone *node_zones = NODE_DATA(dev->id)->node_zones;
- struct zone *zone;
unsigned long res;
+ int i,j;
unsigned long req = strict_strtoul(buf, 10, &res);

if (!req)
return 1; /* zero is no-op */

- for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
- if (!populated_zone(zone))
- continue;
- scan_zone_unevictable_pages(zone);
+ for (j = 0; j < MAX_NR_ZONES; ++j) {
+ for_each_mem_region_in_nid(i, dev->id) {
+ mem_region_t *mem_region = &(NODE_DATA(dev->id)->mem_regions[i]);
+ struct zone *zone = mem_region->zones;
+ if (!populated_zone(zone))
+ continue;
+ scan_zone_unevictable_pages(zone);
+ }
}
return 1;
}
--
1.7.4

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