[PATCH] mm: free_pages opt
Try to streamline free_pages_bulk by ensuring callers don't pass in a
'count' that exceeds the list size.
Some cleanups:
Rename __free_pages_bulk to __free_one_page.
Put the page list manipulation from __free_pages_ok into free_one_page.
Make __free_pages_ok static.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 6b92a94..ad3d020 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -308,7 +308,7 @@
* -- wli
*/
-static inline void __free_pages_bulk (struct page *page,
+static inline void __free_one_page(struct page *page,
struct zone *zone, unsigned int order)
{
unsigned long page_idx;
@@ -383,40 +383,42 @@
* And clear the zone's pages_scanned counter, to hold off the "all pages are
* pinned" detection logic.
*/
-static int
-free_pages_bulk(struct zone *zone, int count,
- struct list_head *list, unsigned int order)
+static void free_pages_bulk(struct zone *zone, int count,
+ struct list_head *list, int order)
{
- struct page *page = NULL;
- int ret = 0;
-
spin_lock(&zone->lock);
zone->all_unreclaimable = 0;
zone->pages_scanned = 0;
- while (!list_empty(list) && count--) {
+ while (count--) {
+ struct page *page;
+
+ BUG_ON(list_empty(list));
page = list_entry(list->prev, struct page, lru);
- /* have to delete it as __free_pages_bulk list manipulates */
+ /* have to delete it as __free_one_page list manipulates */
list_del(&page->lru);
- __free_pages_bulk(page, zone, order);
- ret++;
+ __free_one_page(page, zone, order);
}
spin_unlock(&zone->lock);
- return ret;
}
-void __free_pages_ok(struct page *page, unsigned int order)
+static void free_one_page(struct zone *zone, struct page *page, int order)
+{
+ LIST_HEAD(list);
+ list_add(&page->lru, &list);
+ free_pages_bulk(zone, 1, &list, order);
+}
+
+static void __free_pages_ok(struct page *page, unsigned int order)
{
unsigned long flags;
- LIST_HEAD(list);
int i;
int reserved = 0;
arch_free_page(page, order);
#ifndef CONFIG_MMU
- if (order > 0)
- for (i = 1 ; i < (1 << order) ; ++i)
- __put_page(page + i);
+ for (i = 1 ; i < (1 << order) ; ++i)
+ __put_page(page + i);
#endif
for (i = 0 ; i < (1 << order) ; ++i)
@@ -424,11 +426,10 @@
if (reserved)
return;
- list_add(&page->lru, &list);
- kernel_map_pages(page, 1<<order, 0);
+ kernel_map_pages(page, 1 << order, 0);
local_irq_save(flags);
__mod_page_state(pgfree, 1 << order);
- free_pages_bulk(page_zone(page), 1, &list, order);
+ free_one_page(page_zone(page), page, order);
local_irq_restore(flags);
}
@@ -602,9 +603,8 @@
struct per_cpu_pages *pcp;
pcp = &pset->pcp[i];
- if (pcp->count)
- pcp->count -= free_pages_bulk(zone, pcp->count,
- &pcp->list, 0);
+ free_pages_bulk(zone, pcp->count, &pcp->list, 0);
+ pcp->count = 0;
}
}
local_irq_restore(flags);
@@ -627,8 +627,8 @@
pcp = &pset->pcp[i];
local_irq_save(flags);
- pcp->count -= free_pages_bulk(zone, pcp->count,
- &pcp->list, 0);
+ free_pages_bulk(zone, pcp->count, &pcp->list, 0);
+ pcp->count = 0;
local_irq_restore(flags);
}
}
@@ -719,8 +719,10 @@
__inc_page_state(pgfree);
list_add(&page->lru, &pcp->list);
pcp->count++;
- if (pcp->count >= pcp->high)
- pcp->count -= free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
+ if (pcp->count >= pcp->high) {
+ free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
+ pcp->count -= pcp->batch;
+ }
local_irq_restore(flags);
put_cpu();
}
@@ -759,7 +761,7 @@
again:
cpu = get_cpu();
- if (order == 0) {
+ if (likely(order == 0)) {
struct per_cpu_pages *pcp;
pcp = &zone_pcp(zone, cpu)->pcp[cold];