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Commit bc357f43 authored by Marek Szyprowski's avatar Marek Szyprowski Committed by Linus Torvalds
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mm: cma: remove watermark hacks 



Commits 2139cbe6 ("cma: fix counting of isolated pages") and
d95ea5d1 ("cma: fix watermark checking") introduced a reliable
method of free page accounting when memory is being allocated from CMA
regions, so the workaround introduced earlier by commit 49f223a9
("mm: trigger page reclaim in alloc_contig_range() to stabilise
watermarks") can be finally removed.

Signed-off-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: default avatarMichal Nazarewicz <mina86@mina86.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 2e30abd1

include/linux/mmzone.h

+0 −9
Original line number Diff line number Diff line
@@ -63,10 +63,8 @@ enum { 


#ifdef CONFIG_CMA

#  define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA)

#  define cma_wmark_pages(zone)	zone->min_cma_pages

#else

#  define is_migrate_cma(migratetype) false

#  define cma_wmark_pages(zone) 0

#endif



#define for_each_migratetype_order(order, type) \
@@ -382,13 +380,6 @@ struct zone { 
#ifdef CONFIG_MEMORY_HOTPLUG

	/* see spanned/present_pages for more description */

	seqlock_t		span_seqlock;

#endif

#ifdef CONFIG_CMA

	/*

	 * CMA needs to increase watermark levels during the allocation

	 * process to make sure that the system is not starved.

	 */

	unsigned long		min_cma_pages;

#endif

	struct free_area	free_area[MAX_ORDER];

mm/page_alloc.c

+0 −58
Original line number Diff line number Diff line
@@ -5218,10 +5218,6 @@ static void __setup_per_zone_wmarks(void) 
		zone->watermark[WMARK_LOW]  = min_wmark_pages(zone) + (tmp >> 2);

		zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);



		zone->watermark[WMARK_MIN] += cma_wmark_pages(zone);

		zone->watermark[WMARK_LOW] += cma_wmark_pages(zone);

		zone->watermark[WMARK_HIGH] += cma_wmark_pages(zone);



		setup_zone_migrate_reserve(zone);

		spin_unlock_irqrestore(&zone->lock, flags);

	}
@@ -5766,54 +5762,6 @@ static int __alloc_contig_migrate_range(struct compact_control *cc, 
	return ret > 0 ? 0 : ret;

}



/*

 * Update zone's cma pages counter used for watermark level calculation.

 */

static inline void __update_cma_watermarks(struct zone *zone, int count)

{

	unsigned long flags;

	spin_lock_irqsave(&zone->lock, flags);

	zone->min_cma_pages += count;

	spin_unlock_irqrestore(&zone->lock, flags);

	setup_per_zone_wmarks();

}



/*

 * Trigger memory pressure bump to reclaim some pages in order to be able to

 * allocate 'count' pages in single page units. Does similar work as

 *__alloc_pages_slowpath() function.

 */

static int __reclaim_pages(struct zone *zone, gfp_t gfp_mask, int count)

{

	enum zone_type high_zoneidx = gfp_zone(gfp_mask);

	struct zonelist *zonelist = node_zonelist(0, gfp_mask);

	int did_some_progress = 0;

	int order = 1;



	/*

	 * Increase level of watermarks to force kswapd do his job

	 * to stabilise at new watermark level.

	 */

	__update_cma_watermarks(zone, count);



	/* Obey watermarks as if the page was being allocated */

	while (!zone_watermark_ok(zone, 0, low_wmark_pages(zone), 0, 0)) {

		wake_all_kswapd(order, zonelist, high_zoneidx, zone_idx(zone));



		did_some_progress = __perform_reclaim(gfp_mask, order, zonelist,

						      NULL);

		if (!did_some_progress) {

			/* Exhausted what can be done so it's blamo time */

			out_of_memory(zonelist, gfp_mask, order, NULL, false);

		}

	}



	/* Restore original watermark levels. */

	__update_cma_watermarks(zone, -count);



	return count;

}



/**

 * alloc_contig_range() -- tries to allocate given range of pages

 * @start:	start PFN to allocate
@@ -5837,7 +5785,6 @@ static int __reclaim_pages(struct zone *zone, gfp_t gfp_mask, int count) 
int alloc_contig_range(unsigned long start, unsigned long end,

		       unsigned migratetype)

{

	struct zone *zone = page_zone(pfn_to_page(start));

	unsigned long outer_start, outer_end;

	int ret = 0, order;
@@ -5922,11 +5869,6 @@ int alloc_contig_range(unsigned long start, unsigned long end, 
		goto done;

	}



	/*

	 * Reclaim enough pages to make sure that contiguous allocation

	 * will not starve the system.

	 */

	__reclaim_pages(zone, GFP_HIGHUSER_MOVABLE, end-start);



	/* Grab isolated pages from freelists. */

	outer_end = isolate_freepages_range(&cc, outer_start, end);