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Commit c54ad30c authored by Nick Piggin's avatar Nick Piggin Committed by Linus Torvalds
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[PATCH] mm: pagealloc opt 



Slightly optimise some page allocation and freeing functions by taking
advantage of knowing whether or not interrupts are disabled.

Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent c484d410

mm/page_alloc.c

+11 −7
Original line number Diff line number Diff line
@@ -375,11 +375,10 @@ static int 
free_pages_bulk(struct zone *zone, int count,

		struct list_head *list, unsigned int order)

{

	unsigned long flags;

	struct page *page = NULL;

	int ret = 0;



	spin_lock_irqsave(&zone->lock, flags);

	spin_lock(&zone->lock);

	zone->all_unreclaimable = 0;

	zone->pages_scanned = 0;

	while (!list_empty(list) && count--) {
@@ -389,12 +388,13 @@ free_pages_bulk(struct zone *zone, int count, 
		__free_pages_bulk(page, zone, order);

		ret++;

	}

	spin_unlock_irqrestore(&zone->lock, flags);

	spin_unlock(&zone->lock);

	return ret;

}



void __free_pages_ok(struct page *page, unsigned int order)

{

	unsigned long flags;

	LIST_HEAD(list);

	int i;

	int reserved = 0;
@@ -415,7 +415,9 @@ void __free_pages_ok(struct page *page, unsigned int order) 
	list_add(&page->lru, &list);

	mod_page_state(pgfree, 1 << order);

	kernel_map_pages(page, 1<<order, 0);

	local_irq_save(flags);

	free_pages_bulk(page_zone(page), 1, &list, order);

	local_irq_restore(flags);

}
@@ -539,12 +541,11 @@ static struct page *__rmqueue(struct zone *zone, unsigned int order) 
static int rmqueue_bulk(struct zone *zone, unsigned int order, 

			unsigned long count, struct list_head *list)

{

	unsigned long flags;

	int i;

	int allocated = 0;

	struct page *page;

	

	spin_lock_irqsave(&zone->lock, flags);

	spin_lock(&zone->lock);

	for (i = 0; i < count; ++i) {

		page = __rmqueue(zone, order);

		if (page == NULL)
@@ -552,7 +553,7 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order, 
		allocated++;

		list_add_tail(&page->lru, list);

	}

	spin_unlock_irqrestore(&zone->lock, flags);

	spin_unlock(&zone->lock);

	return allocated;

}
@@ -589,6 +590,7 @@ void drain_remote_pages(void) 
#if defined(CONFIG_PM) || defined(CONFIG_HOTPLUG_CPU)

static void __drain_pages(unsigned int cpu)

{

	unsigned long flags;

	struct zone *zone;

	int i;
@@ -600,8 +602,10 @@ static void __drain_pages(unsigned int cpu) 
			struct per_cpu_pages *pcp;



			pcp = &pset->pcp[i];

			local_irq_save(flags);

			pcp->count -= free_pages_bulk(zone, pcp->count,

						&pcp->list, 0);

			local_irq_restore(flags);

		}

	}

}
@@ -744,7 +748,7 @@ buffered_rmqueue(struct zone *zone, int order, gfp_t gfp_flags) 
		if (pcp->count <= pcp->low)

			pcp->count += rmqueue_bulk(zone, 0,

						pcp->batch, &pcp->list);

		if (pcp->count) {

		if (likely(pcp->count)) {

			page = list_entry(pcp->list.next, struct page, lru);

			list_del(&page->lru);

			pcp->count--;