Commit 3dfa5721 authored by Christoph Lameter's avatar Christoph Lameter Committed by Linus Torvalds

Page allocator: get rid of the list of cold pages

We have repeatedly discussed if the cold pages still have a point. There is
one way to join the two lists: Use a single list and put the cold pages at the
end and the hot pages at the beginning. That way a single list can serve for
both types of allocations.

The discussion of the RFC for this and Mel's measurements indicate that
there may not be too much of a point left to having separate lists for
hot and cold pages (see http://marc.info/?t=119492914200001&r=1&w=2).
Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Martin Bligh <mbligh@mbligh.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5dc33185
...@@ -113,7 +113,7 @@ struct per_cpu_pages { ...@@ -113,7 +113,7 @@ struct per_cpu_pages {
}; };
struct per_cpu_pageset { struct per_cpu_pageset {
struct per_cpu_pages pcp[2]; /* 0: hot. 1: cold */ struct per_cpu_pages pcp;
#ifdef CONFIG_NUMA #ifdef CONFIG_NUMA
s8 expire; s8 expire;
#endif #endif
......
...@@ -901,25 +901,22 @@ static void drain_pages(unsigned int cpu) ...@@ -901,25 +901,22 @@ static void drain_pages(unsigned int cpu)
{ {
unsigned long flags; unsigned long flags;
struct zone *zone; struct zone *zone;
int i;
for_each_zone(zone) { for_each_zone(zone) {
struct per_cpu_pageset *pset; struct per_cpu_pageset *pset;
struct per_cpu_pages *pcp;
if (!populated_zone(zone)) if (!populated_zone(zone))
continue; continue;
pset = zone_pcp(zone, cpu); pset = zone_pcp(zone, cpu);
for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) {
struct per_cpu_pages *pcp;
pcp = &pset->pcp[i]; pcp = &pset->pcp;
local_irq_save(flags); local_irq_save(flags);
free_pages_bulk(zone, pcp->count, &pcp->list, 0); free_pages_bulk(zone, pcp->count, &pcp->list, 0);
pcp->count = 0; pcp->count = 0;
local_irq_restore(flags); local_irq_restore(flags);
} }
}
} }
/* /*
...@@ -993,9 +990,12 @@ static void fastcall free_hot_cold_page(struct page *page, int cold) ...@@ -993,9 +990,12 @@ static void fastcall free_hot_cold_page(struct page *page, int cold)
arch_free_page(page, 0); arch_free_page(page, 0);
kernel_map_pages(page, 1, 0); kernel_map_pages(page, 1, 0);
pcp = &zone_pcp(zone, get_cpu())->pcp[cold]; pcp = &zone_pcp(zone, get_cpu())->pcp;
local_irq_save(flags); local_irq_save(flags);
__count_vm_event(PGFREE); __count_vm_event(PGFREE);
if (cold)
list_add_tail(&page->lru, &pcp->list);
else
list_add(&page->lru, &pcp->list); list_add(&page->lru, &pcp->list);
set_page_private(page, get_pageblock_migratetype(page)); set_page_private(page, get_pageblock_migratetype(page));
pcp->count++; pcp->count++;
...@@ -1054,7 +1054,7 @@ static struct page *buffered_rmqueue(struct zonelist *zonelist, ...@@ -1054,7 +1054,7 @@ static struct page *buffered_rmqueue(struct zonelist *zonelist,
if (likely(order == 0)) { if (likely(order == 0)) {
struct per_cpu_pages *pcp; struct per_cpu_pages *pcp;
pcp = &zone_pcp(zone, cpu)->pcp[cold]; pcp = &zone_pcp(zone, cpu)->pcp;
local_irq_save(flags); local_irq_save(flags);
if (!pcp->count) { if (!pcp->count) {
pcp->count = rmqueue_bulk(zone, 0, pcp->count = rmqueue_bulk(zone, 0,
...@@ -1064,9 +1064,15 @@ static struct page *buffered_rmqueue(struct zonelist *zonelist, ...@@ -1064,9 +1064,15 @@ static struct page *buffered_rmqueue(struct zonelist *zonelist,
} }
/* Find a page of the appropriate migrate type */ /* Find a page of the appropriate migrate type */
if (cold) {
list_for_each_entry_reverse(page, &pcp->list, lru)
if (page_private(page) == migratetype)
break;
} else {
list_for_each_entry(page, &pcp->list, lru) list_for_each_entry(page, &pcp->list, lru)
if (page_private(page) == migratetype) if (page_private(page) == migratetype)
break; break;
}
/* Allocate more to the pcp list if necessary */ /* Allocate more to the pcp list if necessary */
if (unlikely(&page->lru == &pcp->list)) { if (unlikely(&page->lru == &pcp->list)) {
...@@ -1793,12 +1799,9 @@ void show_free_areas(void) ...@@ -1793,12 +1799,9 @@ void show_free_areas(void)
pageset = zone_pcp(zone, cpu); pageset = zone_pcp(zone, cpu);
printk("CPU %4d: Hot: hi:%5d, btch:%4d usd:%4d " printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
"Cold: hi:%5d, btch:%4d usd:%4d\n", cpu, pageset->pcp.high,
cpu, pageset->pcp[0].high, pageset->pcp.batch, pageset->pcp.count);
pageset->pcp[0].batch, pageset->pcp[0].count,
pageset->pcp[1].high, pageset->pcp[1].batch,
pageset->pcp[1].count);
} }
} }
...@@ -2596,17 +2599,11 @@ inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) ...@@ -2596,17 +2599,11 @@ inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
memset(p, 0, sizeof(*p)); memset(p, 0, sizeof(*p));
pcp = &p->pcp[0]; /* hot */ pcp = &p->pcp;
pcp->count = 0; pcp->count = 0;
pcp->high = 6 * batch; pcp->high = 6 * batch;
pcp->batch = max(1UL, 1 * batch); pcp->batch = max(1UL, 1 * batch);
INIT_LIST_HEAD(&pcp->list); INIT_LIST_HEAD(&pcp->list);
pcp = &p->pcp[1]; /* cold*/
pcp->count = 0;
pcp->high = 2 * batch;
pcp->batch = max(1UL, batch/2);
INIT_LIST_HEAD(&pcp->list);
} }
/* /*
...@@ -2619,7 +2616,7 @@ static void setup_pagelist_highmark(struct per_cpu_pageset *p, ...@@ -2619,7 +2616,7 @@ static void setup_pagelist_highmark(struct per_cpu_pageset *p,
{ {
struct per_cpu_pages *pcp; struct per_cpu_pages *pcp;
pcp = &p->pcp[0]; /* hot list */ pcp = &p->pcp;
pcp->high = high; pcp->high = high;
pcp->batch = max(1UL, high/4); pcp->batch = max(1UL, high/4);
if ((high/4) > (PAGE_SHIFT * 8)) if ((high/4) > (PAGE_SHIFT * 8))
......
...@@ -337,7 +337,7 @@ void refresh_cpu_vm_stats(int cpu) ...@@ -337,7 +337,7 @@ void refresh_cpu_vm_stats(int cpu)
* Check if there are pages remaining in this pageset * Check if there are pages remaining in this pageset
* if not then there is nothing to expire. * if not then there is nothing to expire.
*/ */
if (!p->expire || (!p->pcp[0].count && !p->pcp[1].count)) if (!p->expire || !p->pcp.count)
continue; continue;
/* /*
...@@ -352,11 +352,8 @@ void refresh_cpu_vm_stats(int cpu) ...@@ -352,11 +352,8 @@ void refresh_cpu_vm_stats(int cpu)
if (p->expire) if (p->expire)
continue; continue;
if (p->pcp[0].count) if (p->pcp.count)
drain_zone_pages(zone, p->pcp + 0); drain_zone_pages(zone, &p->pcp);
if (p->pcp[1].count)
drain_zone_pages(zone, p->pcp + 1);
#endif #endif
} }
...@@ -693,20 +690,17 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat, ...@@ -693,20 +690,17 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
"\n pagesets"); "\n pagesets");
for_each_online_cpu(i) { for_each_online_cpu(i) {
struct per_cpu_pageset *pageset; struct per_cpu_pageset *pageset;
int j;
pageset = zone_pcp(zone, i); pageset = zone_pcp(zone, i);
for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
seq_printf(m, seq_printf(m,
"\n cpu: %i pcp: %i" "\n cpu: %i"
"\n count: %i" "\n count: %i"
"\n high: %i" "\n high: %i"
"\n batch: %i", "\n batch: %i",
i, j, i,
pageset->pcp[j].count, pageset->pcp.count,
pageset->pcp[j].high, pageset->pcp.high,
pageset->pcp[j].batch); pageset->pcp.batch);
}
#ifdef CONFIG_SMP #ifdef CONFIG_SMP
seq_printf(m, "\n vm stats threshold: %d", seq_printf(m, "\n vm stats threshold: %d",
pageset->stat_threshold); pageset->stat_threshold);
......
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