[PATCH] mm: remove zone->prev_prioriy

KOSAKI Motohiro
2009-02-10T09:42:37Z

KAMEZAWA Hiroyuki sugessted to remove zone->prev_priority.
it's because Split-LRU VM doesn't use this parameter at all.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
---
include/linux/memcontrol.h | 27 -------------------------
include/linux/mmzone.h | 15 --------------
mm/memcontrol.c | 31 -----------------------------
mm/page_alloc.c | 2 -
mm/vmscan.c | 48 ++-------------------------------------------
mm/vmstat.c | 2 -
6 files changed, 3 insertions(+), 122 deletions(-)

Index: b/mm/memcontrol.c
===================================================================
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -150,8 +150,6 @@ struct mem_cgroup {
*/
spinlock_t reclaim_param_lock;

- int prev_priority; /* for recording reclaim priority */
-
/*
* While reclaiming in a hiearchy, we cache the last child we
* reclaimed from. Protected by hierarchy_mutex
@@ -464,35 +462,6 @@ int mem_cgroup_calc_mapped_ratio(struct
return (int)((rss * 100L) / total);
}

-/*
- * prev_priority control...this will be used in memory reclaim path.
- */
-int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem)
-{
- int prev_priority;
-
- spin_lock(&mem->reclaim_param_lock);
- prev_priority = mem->prev_priority;
- spin_unlock(&mem->reclaim_param_lock);
-
- return prev_priority;
-}
-
-void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority)
-{
- spin_lock(&mem->reclaim_param_lock);
- if (priority < mem->prev_priority)
- mem->prev_priority = priority;
- spin_unlock(&mem->reclaim_param_lock);
-}
-
-void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority)
-{
- spin_lock(&mem->reclaim_param_lock);
- mem->prev_priority = priority;
- spin_unlock(&mem->reclaim_param_lock);
-}
-
static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages)
{
unsigned long active;
Index: b/mm/vmscan.c
===================================================================
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1174,20 +1174,6 @@ done:
}

/*
- * We are about to scan this zone at a certain priority level. If that priority
- * level is smaller (ie: more urgent) than the previous priority, then note
- * that priority level within the zone. This is done so that when the next
- * process comes in to scan this zone, it will immediately start out at this
- * priority level rather than having to build up its own scanning priority.
- * Here, this priority affects only the reclaim-mapped threshold.
- */
-static inline void note_zone_scanning_priority(struct zone *zone, int priority)
-{
- if (priority < zone->prev_priority)
- zone->prev_priority = priority;
-}
-
-/*
* This moves pages from the active list to the inactive list.
*
* We move them the other way if the page is referenced by one or more
@@ -1553,22 +1539,18 @@ static void shrink_zones(int priority, s
if (scanning_global_lru(sc)) {
if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
continue;
- note_zone_scanning_priority(zone, priority);

if (zone_is_all_unreclaimable(zone) &&
priority != DEF_PRIORITY)
continue; /* Let kswapd poll it */
- sc->all_unreclaimable = 0;
+
} else {
/*
* Ignore cpuset limitation here. We just want to reduce
* # of used pages by us regardless of memory shortage.
*/
- sc->all_unreclaimable = 0;
- mem_cgroup_note_reclaim_priority(sc->mem_cgroup,
- priority);
}
-
+ sc->all_unreclaimable = 0;
shrink_zone(priority, zone, sc);
}
}
@@ -1676,11 +1658,8 @@ out:

if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
continue;
-
- zone->prev_priority = priority;
}
- } else
- mem_cgroup_record_reclaim_priority(sc->mem_cgroup, priority);
+ }

delayacct_freepages_end();

@@ -1769,11 +1748,6 @@ static unsigned long balance_pgdat(pg_da
.mem_cgroup = NULL,
.isolate_pages = isolate_pages_global,
};
- /*
- * temp_priority is used to remember the scanning priority at which
- * this zone was successfully refilled to free_pages == pages_high.
- */
- int temp_priority[MAX_NR_ZONES];

loop_again:
total_scanned = 0;
@@ -1781,9 +1755,6 @@ loop_again:
sc.may_writepage = !laptop_mode;
count_vm_event(PAGEOUTRUN);

- for (i = 0; i < pgdat->nr_zones; i++)
- temp_priority[i] = DEF_PRIORITY;
-
for (priority = DEF_PRIORITY; priority >= 0; priority--) {
int end_zone = 0; /* Inclusive. 0 = ZONE_DMA */
unsigned long lru_pages = 0;
@@ -1854,9 +1825,7 @@ loop_again:
if (!zone_watermark_ok(zone, order, zone->pages_high,
end_zone, 0))
all_zones_ok = 0;
- temp_priority[i] = priority;
sc.nr_scanned = 0;
- note_zone_scanning_priority(zone, priority);
/*
* We put equal pressure on every zone, unless one
* zone has way too many pages free already.
@@ -1903,16 +1872,6 @@ loop_again:
break;
}
out:
- /*
- * Note within each zone the priority level at which this zone was
- * brought into a happy state. So that the next thread which scans this
- * zone will start out at that priority level.
- */
- for (i = 0; i < pgdat->nr_zones; i++) {
- struct zone *zone = pgdat->node_zones + i;
-
- zone->prev_priority = temp_priority[i];
- }
if (!all_zones_ok) {
cond_resched();

@@ -2321,7 +2280,6 @@ static int __zone_reclaim(struct zone *z
*/
priority = ZONE_RECLAIM_PRIORITY;
do {
- note_zone_scanning_priority(zone, priority);
shrink_zone(priority, zone, &sc);
priority--;
} while (priority >= 0 && sc.nr_reclaimed < nr_pages);
Index: b/include/linux/mmzone.h
===================================================================
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -337,21 +337,6 @@ struct zone {
atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];

/*
- * prev_priority holds the scanning priority for this zone. It is
- * defined as the scanning priority at which we achieved our reclaim
- * target at the previous try_to_free_pages() or balance_pgdat()
- * invokation.
- *
- * We use prev_priority as a measure of how much stress page reclaim is
- * under - it drives the swappiness decision: whether to unmap mapped
- * pages.
- *
- * Access to both this field is quite racy even on uniprocessor. But
- * it is expected to average out OK.
- */
- int prev_priority;
-
- /*
* The target ratio of ACTIVE_ANON to INACTIVE_ANON pages on
* this zone's LRU. Maintained by the pageout code.
*/
Index: b/mm/page_alloc.c
===================================================================
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3516,8 +3516,6 @@ static void __paginginit free_area_init_
zone_seqlock_init(zone);
zone->zone_pgdat = pgdat;

- zone->prev_priority = DEF_PRIORITY;
-
zone_pcp_init(zone);
for_each_lru(l) {
INIT_LIST_HEAD(&zone->lru[l].list);
Index: b/mm/vmstat.c
===================================================================
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -775,11 +775,9 @@ static void zoneinfo_show_print(struct s
}
seq_printf(m,
"\n all_unreclaimable: %u"
- "\n prev_priority: %i"
"\n start_pfn: %lu"
"\n inactive_ratio: %u",
zone_is_all_unreclaimable(zone),
- zone->prev_priority,
zone->zone_start_pfn,
zone->inactive_ratio);
seq_putc(m, '\n');
Index: b/include/linux/memcontrol.h
===================================================================
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -88,14 +88,7 @@ extern void mem_cgroup_end_migration(str
/*
* For memory reclaim.
*/
-extern int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem);
extern long mem_cgroup_reclaim_imbalance(struct mem_cgroup *mem);
-
-extern int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem);
-extern void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem,
- int priority);
-extern void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem,
- int priority);
int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg);
unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
struct zone *zone,
@@ -209,31 +202,11 @@ static inline void mem_cgroup_end_migrat
{
}

-static inline int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem)
-{
- return 0;
-}
-
static inline int mem_cgroup_reclaim_imbalance(struct mem_cgroup *mem)
{
return 0;
}

-static inline int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem)
-{
- return 0;
-}
-
-static inline void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem,
- int priority)
-{
-}
-
-static inline void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem,
- int priority)
-{
-}
-
static inline bool mem_cgroup_disabled(void)
{
return true;