Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 2fe86e00 authored by Michal Nazarewicz's avatar Michal Nazarewicz Committed by Marek Szyprowski
Browse files

mm: compaction: introduce isolate_migratepages_range() 



This commit introduces isolate_migratepages_range() function which
extracts functionality from isolate_migratepages() so that it can be
used on arbitrary PFN ranges.

isolate_migratepages() function is implemented as a simple wrapper
around isolate_migratepages_range().

Signed-off-by: default avatarMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Acked-by: default avatarMel Gorman <mel@csn.ul.ie>
Reviewed-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: default avatarRob Clark <rob.clark@linaro.org>
Tested-by: default avatarOhad Ben-Cohen <ohad@wizery.com>
Tested-by: default avatarBenjamin Gaignard <benjamin.gaignard@linaro.org>
Tested-by: default avatarRobert Nelson <robertcnelson@gmail.com>
Tested-by: default avatarBarry Song <Baohua.Song@csr.com>
parent 5f63b720

mm/compaction.c

+54 −21
Original line number Diff line number Diff line
@@ -250,31 +250,34 @@ typedef enum { 
	ISOLATE_SUCCESS,	/* Pages isolated, migrate */

} isolate_migrate_t;



/*

 * Isolate all pages that can be migrated from the block pointed to by

 * the migrate scanner within compact_control.

/**

 * isolate_migratepages_range() - isolate all migrate-able pages in range.

 * @zone:	Zone pages are in.

 * @cc:		Compaction control structure.

 * @low_pfn:	The first PFN of the range.

 * @end_pfn:	The one-past-the-last PFN of the range.

 *

 * Isolate all pages that can be migrated from the range specified by

 * [low_pfn, end_pfn).  Returns zero if there is a fatal signal

 * pending), otherwise PFN of the first page that was not scanned

 * (which may be both less, equal to or more then end_pfn).

 *

 * Assumes that cc->migratepages is empty and cc->nr_migratepages is

 * zero.

 *

 * Apart from cc->migratepages and cc->nr_migratetypes this function

 * does not modify any cc's fields, in particular it does not modify

 * (or read for that matter) cc->migrate_pfn.

 */

static isolate_migrate_t isolate_migratepages(struct zone *zone,

					struct compact_control *cc)

static unsigned long

isolate_migratepages_range(struct zone *zone, struct compact_control *cc,

			   unsigned long low_pfn, unsigned long end_pfn)

{

	unsigned long low_pfn, end_pfn;

	unsigned long last_pageblock_nr = 0, pageblock_nr;

	unsigned long nr_scanned = 0, nr_isolated = 0;

	struct list_head *migratelist = &cc->migratepages;

	isolate_mode_t mode = ISOLATE_ACTIVE|ISOLATE_INACTIVE;



	/* Do not scan outside zone boundaries */

	low_pfn = max(cc->migrate_pfn, zone->zone_start_pfn);



	/* Only scan within a pageblock boundary */

	end_pfn = ALIGN(low_pfn + pageblock_nr_pages, pageblock_nr_pages);



	/* Do not cross the free scanner or scan within a memory hole */

	if (end_pfn > cc->free_pfn || !pfn_valid(low_pfn)) {

		cc->migrate_pfn = end_pfn;

		return ISOLATE_NONE;

	}



	/*

	 * Ensure that there are not too many pages isolated from the LRU

	 * list by either parallel reclaimers or compaction. If there are,
@@ -283,12 +286,12 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone, 
	while (unlikely(too_many_isolated(zone))) {

		/* async migration should just abort */

		if (!cc->sync)

			return ISOLATE_ABORT;

			return 0;



		congestion_wait(BLK_RW_ASYNC, HZ/10);



		if (fatal_signal_pending(current))

			return ISOLATE_ABORT;

			return 0;

	}



	/* Time to isolate some pages for migration */
@@ -396,10 +399,40 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone, 
	acct_isolated(zone, cc);



	spin_unlock_irq(&zone->lru_lock);

	cc->migrate_pfn = low_pfn;



	trace_mm_compaction_isolate_migratepages(nr_scanned, nr_isolated);



	return low_pfn;

}



/*

 * Isolate all pages that can be migrated from the block pointed to by

 * the migrate scanner within compact_control.

 */

static isolate_migrate_t isolate_migratepages(struct zone *zone,

					struct compact_control *cc)

{

	unsigned long low_pfn, end_pfn;



	/* Do not scan outside zone boundaries */

	low_pfn = max(cc->migrate_pfn, zone->zone_start_pfn);



	/* Only scan within a pageblock boundary */

	end_pfn = ALIGN(low_pfn + pageblock_nr_pages, pageblock_nr_pages);



	/* Do not cross the free scanner or scan within a memory hole */

	if (end_pfn > cc->free_pfn || !pfn_valid(low_pfn)) {

		cc->migrate_pfn = end_pfn;

		return ISOLATE_NONE;

	}



	/* Perform the isolation */

	low_pfn = isolate_migratepages_range(zone, cc, low_pfn, end_pfn);

	if (!low_pfn)

		return ISOLATE_ABORT;



	cc->migrate_pfn = low_pfn;



	return ISOLATE_SUCCESS;

}