[PATCH 17/22] mm: page allocator: Move magazine access behind accessors

Mel Gorman
2013-05-08T16:03:24Z

In preparation for splitting the magazines, move them behind accessors.

Signed-off-by: Mel Gorman <mgorman@suse.de>
---
include/linux/mmzone.h | 4 ++--
mm/page_alloc.c | 57 +++++++++++++++++++++++++++++++++-----------------
mm/vmstat.c | 5 +----
3 files changed, 41 insertions(+), 25 deletions(-)

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index ca04853..4eb5151 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -370,8 +370,8 @@ struct zone {
* Keep some order-0 pages on a separate free list
* protected by an irq-unsafe lock
*/
- spinlock_t magazine_lock;
- struct free_area_magazine noirq_magazine;
+ spinlock_t _magazine_lock;
+ struct free_area_magazine _noirq_magazine;

#ifndef CONFIG_SPARSEMEM
/*
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 6760e00..36ffff0 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1074,11 +1074,33 @@ void mark_free_pages(struct zone *zone)
#define MAGAZINE_ALLOC_BATCH (384)
#define MAGAZINE_FREE_BATCH (64)

+static inline struct free_area_magazine *find_lock_magazine(struct zone *zone)
+{
+ struct free_area_magazine *area = &zone->_noirq_magazine;
+ spin_lock(&zone->_magazine_lock);
+ return area;
+}
+
+static inline struct free_area_magazine *find_lock_filled_magazine(struct zone *zone)
+{
+ struct free_area_magazine *area = &zone->_noirq_magazine;
+ if (!area->nr_free)
+ return NULL;
+ spin_lock(&zone->_magazine_lock);
+ return area;
+}
+
+static inline void unlock_magazine(struct free_area_magazine *area)
+{
+ struct zone *zone = container_of(area, struct zone, _noirq_magazine);
+ spin_unlock(&zone->_magazine_lock);
+}
+
static
-struct page *__rmqueue_magazine(struct zone *zone, int migratetype)
+struct page *__rmqueue_magazine(struct free_area_magazine *area,
+ int migratetype)
{
struct page *page;
- struct free_area_magazine *area = &(zone->noirq_magazine);

if (list_empty(&area->free_list[migratetype]))
return NULL;
@@ -1092,9 +1114,9 @@ struct page *__rmqueue_magazine(struct zone *zone, int migratetype)
return page;
}

-static void magazine_drain(struct zone *zone, int migratetype)
+static void magazine_drain(struct zone *zone, struct free_area_magazine *area,
+ int migratetype)
{
- struct free_area_magazine *area = &(zone->noirq_magazine);
struct list_head *list;
struct page *page;
unsigned int batch_free = 0;
@@ -1104,7 +1126,7 @@ static void magazine_drain(struct zone *zone, int migratetype)
LIST_HEAD(free_list);

if (area->nr_free < MAGAZINE_LIMIT) {
- spin_unlock(&zone->magazine_lock);
+ unlock_magazine(area);
return;
}

@@ -1139,7 +1161,7 @@ static void magazine_drain(struct zone *zone, int migratetype)
}

/* Free the list of pages to the buddy allocator */
- spin_unlock(&zone->magazine_lock);
+ unlock_magazine(area);
spin_lock_irqsave(&zone->lock, flags);
while (!list_empty(&free_list)) {
page = list_entry(free_list.prev, struct page, lru);
@@ -1188,13 +1210,12 @@ void free_base_page(struct page *page)
}

/* Put the free page on the magazine list */
- spin_lock(&zone->magazine_lock);
- area = &(zone->noirq_magazine);
+ area = find_lock_magazine(zone);
list_add(&page->lru, &area->free_list[migratetype]);
area->nr_free++;

/* Drain the magazine if necessary, releases the magazine lock */
- magazine_drain(zone, migratetype);
+ magazine_drain(zone, area, migratetype);
}

/* Free a list of 0-order pages */
@@ -1307,20 +1328,18 @@ static
struct page *rmqueue_magazine(struct zone *zone, int migratetype)
{
struct page *page = NULL;
+ struct free_area_magazine *area = find_lock_filled_magazine(zone);

- /* Only acquire the lock if there is a reasonable chance of success */
- if (zone->noirq_magazine.nr_free) {
- spin_lock(&zone->magazine_lock);
retry:
- page = __rmqueue_magazine(zone, migratetype);
- spin_unlock(&zone->magazine_lock);
+ if (area) {
+ page = __rmqueue_magazine(area, migratetype);
+ unlock_magazine(area);
}

/* Try refilling the magazine on allocaion failure */
if (!page) {
LIST_HEAD(alloc_list);
unsigned long flags;
- struct free_area_magazine *area = &(zone->noirq_magazine);
unsigned int i;
unsigned int nr_alloced = 0;

@@ -1340,7 +1359,7 @@ retry:
if (!nr_alloced)
return NULL;

- spin_lock(&zone->magazine_lock);
+ area = find_lock_magazine(zone);
list_splice(&alloc_list, &area->free_list[migratetype]);
area->nr_free += nr_alloced;
goto retry;
@@ -3782,8 +3801,8 @@ static void __meminit zone_init_free_lists(struct zone *zone)
for_each_migratetype_order(order, t) {
INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
zone->free_area[order].nr_free = 0;
- INIT_LIST_HEAD(&zone->noirq_magazine.free_list[t]);
- zone->noirq_magazine.nr_free = 0;
+ INIT_LIST_HEAD(&zone->_noirq_magazine.free_list[t]);
+ zone->_noirq_magazine.nr_free = 0;
}
}

@@ -4333,7 +4352,7 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat,
zone->name = zone_names[j];
spin_lock_init(&zone->lock);
spin_lock_init(&zone->lru_lock);
- spin_lock_init(&zone->magazine_lock);
+ spin_lock_init(&zone->_magazine_lock);
zone_seqlock_init(zone);
zone->zone_pgdat = pgdat;

diff --git a/mm/vmstat.c b/mm/vmstat.c
index 7274ca5..3db0d52 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1003,15 +1003,12 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
")"
"\n noirq magazine");
seq_printf(m,
- "\n cpu: %i"
"\n count: %lu",
- i,
- zone->noirq_magazine.nr_free);
+ zone->_noirq_magazine.nr_free);

#ifdef CONFIG_SMP
for_each_online_cpu(i) {
struct per_cpu_pageset *pageset;
-
pageset = per_cpu_ptr(zone->pageset, i);
seq_printf(m, "\n pagesets\n vm stats threshold: %d",
pageset->stat_threshold);
--
1.8.1.4