lkml.org 
[lkml]   [2009]   [Aug]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3/3] page-allocator: Move pcp static fields for high and batch off-pcp and onto the zone
Date
Having multiple lists per PCPU increased the size of the per-pcpu
structure. Two of the fields, high and batch, do not change within a
zone making that information redundant. This patch moves those fields
off the PCP and onto the zone to reduce the size of the PCPU.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
---
include/linux/mmzone.h | 9 +++++----
mm/page_alloc.c | 47 +++++++++++++++++++++++++----------------------
mm/vmstat.c | 4 ++--
3 files changed, 32 insertions(+), 28 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 6e0b624..57a3ef0 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -167,12 +167,10 @@ enum zone_watermarks {
#define high_wmark_pages(z) (z->watermark[WMARK_HIGH])

struct per_cpu_pages {
- int count; /* number of pages in the list */
- int high; /* high watermark, emptying needed */
- int batch; /* chunk size for buddy add/remove */
-
/* Lists of pages, one per migrate type stored on the pcp-lists */
struct list_head lists[MIGRATE_PCPTYPES];
+
+ int count; /* number of pages in the list */
};

struct per_cpu_pageset {
@@ -284,6 +282,9 @@ struct zone {
/* zone watermarks, access with *_wmark_pages(zone) macros */
unsigned long watermark[NR_WMARK];

+ int pcp_high; /* high watermark, emptying needed */
+ int pcp_batch; /* chunk size for buddy add/remove */
+
/*
* We don't know if the memory that we're going to allocate will be freeable
* or/and it will be released eventually, so to avoid totally wasting several
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index dd3f306..65cdfbf 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -988,8 +988,8 @@ void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
int to_drain;

local_irq_save(flags);
- if (pcp->count >= pcp->batch)
- to_drain = pcp->batch;
+ if (pcp->count >= zone->pcp_batch)
+ to_drain = zone->pcp_batch;
else
to_drain = pcp->count;
free_pcppages_bulk(zone, to_drain, pcp);
@@ -1129,9 +1129,9 @@ static void free_hot_cold_page(struct page *page, int cold)
else
list_add(&page->lru, &pcp->lists[migratetype]);
pcp->count++;
- if (pcp->count >= pcp->high) {
- free_pcppages_bulk(zone, pcp->batch, pcp);
- pcp->count -= pcp->batch;
+ if (pcp->count >= zone->pcp_high) {
+ free_pcppages_bulk(zone, zone->pcp_batch, pcp);
+ pcp->count -= zone->pcp_batch;
}

out:
@@ -1199,7 +1199,7 @@ again:
local_irq_save(flags);
if (list_empty(list)) {
pcp->count += rmqueue_bulk(zone, 0,
- pcp->batch, list,
+ zone->pcp_batch, list,
migratetype, cold);
if (unlikely(list_empty(list)))
goto failed;
@@ -2178,8 +2178,8 @@ void show_free_areas(void)
pageset = zone_pcp(zone, cpu);

printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
- cpu, pageset->pcp.high,
- pageset->pcp.batch, pageset->pcp.count);
+ cpu, zone->pcp_high,
+ zone->pcp_batch, pageset->pcp.count);
}
}

@@ -3045,7 +3045,9 @@ static int zone_batchsize(struct zone *zone)
#endif
}

-static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
+static void setup_pageset(struct zone *zone,
+ struct per_cpu_pageset *p,
+ unsigned long batch)
{
struct per_cpu_pages *pcp;
int migratetype;
@@ -3054,8 +3056,8 @@ static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)

pcp = &p->pcp;
pcp->count = 0;
- pcp->high = 6 * batch;
- pcp->batch = max(1UL, 1 * batch);
+ zone->pcp_high = 6 * batch;
+ zone->pcp_batch = max(1UL, 1 * batch);
for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
INIT_LIST_HEAD(&pcp->lists[migratetype]);
}
@@ -3065,16 +3067,17 @@ static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
* to the value high for the pageset p.
*/

-static void setup_pagelist_highmark(struct per_cpu_pageset *p,
+static void setup_pagelist_highmark(struct zone *zone,
+ struct per_cpu_pageset *p,
unsigned long high)
{
struct per_cpu_pages *pcp;

pcp = &p->pcp;
- pcp->high = high;
- pcp->batch = max(1UL, high/4);
+ zone->pcp_high = high;
+ zone->pcp_batch = max(1UL, high/4);
if ((high/4) > (PAGE_SHIFT * 8))
- pcp->batch = PAGE_SHIFT * 8;
+ zone->pcp_batch = PAGE_SHIFT * 8;
}


@@ -3115,10 +3118,10 @@ static int __cpuinit process_zones(int cpu)
if (!zone_pcp(zone, cpu))
goto bad;

- setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
+ setup_pageset(zone, zone_pcp(zone, cpu), zone_batchsize(zone));

if (percpu_pagelist_fraction)
- setup_pagelist_highmark(zone_pcp(zone, cpu),
+ setup_pagelist_highmark(zone, zone_pcp(zone, cpu),
(zone->present_pages / percpu_pagelist_fraction));
}

@@ -3250,7 +3253,7 @@ static int __zone_pcp_update(void *data)

local_irq_save(flags);
free_pcppages_bulk(zone, pcp->count, pcp);
- setup_pageset(pset, batch);
+ setup_pageset(zone, pset, batch);
local_irq_restore(flags);
}
return 0;
@@ -3270,9 +3273,9 @@ static __meminit void zone_pcp_init(struct zone *zone)
#ifdef CONFIG_NUMA
/* Early boot. Slab allocator not functional yet */
zone_pcp(zone, cpu) = &boot_pageset[cpu];
- setup_pageset(&boot_pageset[cpu],0);
+ setup_pageset(zone, &boot_pageset[cpu],0);
#else
- setup_pageset(zone_pcp(zone,cpu), batch);
+ setup_pageset(zone, zone_pcp(zone,cpu), batch);
#endif
}
if (zone->present_pages)
@@ -4781,7 +4784,7 @@ int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
}

/*
- * percpu_pagelist_fraction - changes the pcp->high for each zone on each
+ * percpu_pagelist_fraction - changes the zone->pcp_high for each zone on each
* cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
* can have before it gets flushed back to buddy allocator.
*/
@@ -4800,7 +4803,7 @@ int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
for_each_online_cpu(cpu) {
unsigned long high;
high = zone->present_pages / percpu_pagelist_fraction;
- setup_pagelist_highmark(zone_pcp(zone, cpu), high);
+ setup_pagelist_highmark(zone, zone_pcp(zone, cpu), high);
}
}
return 0;
diff --git a/mm/vmstat.c b/mm/vmstat.c
index c81321f..a9d23c3 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -746,8 +746,8 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
"\n batch: %i",
i,
pageset->pcp.count,
- pageset->pcp.high,
- pageset->pcp.batch);
+ zone->pcp_high,
+ zone->pcp_batch);
#ifdef CONFIG_SMP
seq_printf(m, "\n vm stats threshold: %d",
pageset->stat_threshold);
--
1.6.3.3


\
 
 \ /
  Last update: 2009-08-18 13:19    [W:0.148 / U:0.596 seconds]
©2003-2014 Jasper Spaans. Advertise on this site