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Commit e0b9daeb authored by David Rientjes's avatar David Rientjes Committed by Linus Torvalds
Browse files

mm, compaction: embed migration mode in compact_control 



We're going to want to manipulate the migration mode for compaction in the
page allocator, and currently compact_control's sync field is only a bool.

Currently, we only do MIGRATE_ASYNC or MIGRATE_SYNC_LIGHT compaction
depending on the value of this bool.  Convert the bool to enum
migrate_mode and pass the migration mode in directly.  Later, we'll want
to avoid MIGRATE_SYNC_LIGHT for thp allocations in the pagefault patch to
avoid unnecessary latency.

This also alters compaction triggered from sysfs, either for the entire
system or for a node, to force MIGRATE_SYNC.

[akpm@linux-foundation.org: fix build]
[iamjoonsoo.kim@lge.com: use MIGRATE_SYNC in alloc_contig_range()]
Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
Suggested-by: default avatarMel Gorman <mgorman@suse.de>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Cc: Greg Thelen <gthelen@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 35979ef3

include/linux/compaction.h

+2 −2
Original line number Diff line number Diff line
@@ -22,7 +22,7 @@ extern int sysctl_extfrag_handler(struct ctl_table *table, int write, 
extern int fragmentation_index(struct zone *zone, unsigned int order);

extern unsigned long try_to_compact_pages(struct zonelist *zonelist,

			int order, gfp_t gfp_mask, nodemask_t *mask,

			bool sync, bool *contended);

			enum migrate_mode mode, bool *contended);

extern void compact_pgdat(pg_data_t *pgdat, int order);

extern void reset_isolation_suitable(pg_data_t *pgdat);

extern unsigned long compaction_suitable(struct zone *zone, int order);
@@ -91,7 +91,7 @@ static inline bool compaction_restarting(struct zone *zone, int order) 
#else

static inline unsigned long try_to_compact_pages(struct zonelist *zonelist,

			int order, gfp_t gfp_mask, nodemask_t *nodemask,

			bool sync, bool *contended)

			enum migrate_mode mode, bool *contended)

{

	return COMPACT_CONTINUE;

}

mm/compaction.c

+19 −17
Original line number Diff line number Diff line
@@ -161,7 +161,8 @@ static void update_pageblock_skip(struct compact_control *cc, 
			return;

		if (pfn > zone->compact_cached_migrate_pfn[0])

			zone->compact_cached_migrate_pfn[0] = pfn;

		if (cc->sync && pfn > zone->compact_cached_migrate_pfn[1])

		if (cc->mode != MIGRATE_ASYNC &&

		    pfn > zone->compact_cached_migrate_pfn[1])

			zone->compact_cached_migrate_pfn[1] = pfn;

	} else {

		if (cc->finished_update_free)
@@ -208,7 +209,7 @@ static bool compact_checklock_irqsave(spinlock_t *lock, unsigned long *flags, 
		}



		/* async aborts if taking too long or contended */

		if (!cc->sync) {

		if (cc->mode == MIGRATE_ASYNC) {

			cc->contended = true;

			return false;

		}
@@ -473,7 +474,8 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, 
	bool locked = false;

	struct page *page = NULL, *valid_page = NULL;

	bool set_unsuitable = true;

	const isolate_mode_t mode = (!cc->sync ? ISOLATE_ASYNC_MIGRATE : 0) |

	const isolate_mode_t mode = (cc->mode == MIGRATE_ASYNC ?

					ISOLATE_ASYNC_MIGRATE : 0) |

				    (unevictable ? ISOLATE_UNEVICTABLE : 0);



	/*
@@ -483,7 +485,7 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, 
	 */

	while (unlikely(too_many_isolated(zone))) {

		/* async migration should just abort */

		if (!cc->sync)

		if (cc->mode == MIGRATE_ASYNC)

			return 0;



		congestion_wait(BLK_RW_ASYNC, HZ/10);
@@ -548,7 +550,8 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, 
			 * the minimum amount of work satisfies the allocation

			 */

			mt = get_pageblock_migratetype(page);

			if (!cc->sync && !migrate_async_suitable(mt)) {

			if (cc->mode == MIGRATE_ASYNC &&

			    !migrate_async_suitable(mt)) {

				set_unsuitable = false;

				goto next_pageblock;

			}
@@ -981,6 +984,7 @@ static int compact_zone(struct zone *zone, struct compact_control *cc) 
	int ret;

	unsigned long start_pfn = zone->zone_start_pfn;

	unsigned long end_pfn = zone_end_pfn(zone);

	const bool sync = cc->mode != MIGRATE_ASYNC;



	ret = compaction_suitable(zone, cc->order);

	switch (ret) {
@@ -1006,7 +1010,7 @@ static int compact_zone(struct zone *zone, struct compact_control *cc) 
	 * information on where the scanners should start but check that it

	 * is initialised by ensuring the values are within zone boundaries.

	 */

	cc->migrate_pfn = zone->compact_cached_migrate_pfn[cc->sync];

	cc->migrate_pfn = zone->compact_cached_migrate_pfn[sync];

	cc->free_pfn = zone->compact_cached_free_pfn;

	if (cc->free_pfn < start_pfn || cc->free_pfn > end_pfn) {

		cc->free_pfn = end_pfn & ~(pageblock_nr_pages-1);
@@ -1040,8 +1044,7 @@ static int compact_zone(struct zone *zone, struct compact_control *cc) 


		nr_migrate = cc->nr_migratepages;

		err = migrate_pages(&cc->migratepages, compaction_alloc,

				compaction_free, (unsigned long)cc,

				cc->sync ? MIGRATE_SYNC_LIGHT : MIGRATE_ASYNC,

				compaction_free, (unsigned long)cc, cc->mode,

				MR_COMPACTION);

		update_nr_listpages(cc);

		nr_remaining = cc->nr_migratepages;
@@ -1074,9 +1077,8 @@ static int compact_zone(struct zone *zone, struct compact_control *cc) 
	return ret;

}



static unsigned long compact_zone_order(struct zone *zone,

				 int order, gfp_t gfp_mask,

				 bool sync, bool *contended)

static unsigned long compact_zone_order(struct zone *zone, int order,

		gfp_t gfp_mask, enum migrate_mode mode, bool *contended)

{

	unsigned long ret;

	struct compact_control cc = {
@@ -1085,7 +1087,7 @@ static unsigned long compact_zone_order(struct zone *zone, 
		.order = order,

		.migratetype = allocflags_to_migratetype(gfp_mask),

		.zone = zone,

		.sync = sync,

		.mode = mode,

	};

	INIT_LIST_HEAD(&cc.freepages);

	INIT_LIST_HEAD(&cc.migratepages);
@@ -1107,7 +1109,7 @@ int sysctl_extfrag_threshold = 500; 
 * @order: The order of the current allocation

 * @gfp_mask: The GFP mask of the current allocation

 * @nodemask: The allowed nodes to allocate from

 * @sync: Whether migration is synchronous or not

 * @mode: The migration mode for async, sync light, or sync migration

 * @contended: Return value that is true if compaction was aborted due to lock contention

 * @page: Optionally capture a free page of the requested order during compaction

 *
@@ -1115,7 +1117,7 @@ int sysctl_extfrag_threshold = 500; 
 */

unsigned long try_to_compact_pages(struct zonelist *zonelist,

			int order, gfp_t gfp_mask, nodemask_t *nodemask,

			bool sync, bool *contended)

			enum migrate_mode mode, bool *contended)

{

	enum zone_type high_zoneidx = gfp_zone(gfp_mask);

	int may_enter_fs = gfp_mask & __GFP_FS;
@@ -1140,7 +1142,7 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist, 
								nodemask) {

		int status;



		status = compact_zone_order(zone, order, gfp_mask, sync,

		status = compact_zone_order(zone, order, gfp_mask, mode,

						contended);

		rc = max(status, rc);
@@ -1190,7 +1192,7 @@ void compact_pgdat(pg_data_t *pgdat, int order) 
{

	struct compact_control cc = {

		.order = order,

		.sync = false,

		.mode = MIGRATE_ASYNC,

	};



	if (!order)
@@ -1203,7 +1205,7 @@ static void compact_node(int nid) 
{

	struct compact_control cc = {

		.order = -1,

		.sync = true,

		.mode = MIGRATE_SYNC,

		.ignore_skip_hint = true,

	};

mm/internal.h

+1 −1
Original line number Diff line number Diff line
@@ -134,7 +134,7 @@ struct compact_control { 
	unsigned long nr_migratepages;	/* Number of pages to migrate */

	unsigned long free_pfn;		/* isolate_freepages search base */

	unsigned long migrate_pfn;	/* isolate_migratepages search base */

	bool sync;			/* Synchronous migration */

	enum migrate_mode mode;		/* Async or sync migration mode */

	bool ignore_skip_hint;		/* Scan blocks even if marked skip */

	bool finished_update_free;	/* True when the zone cached pfns are

					 * no longer being updated

mm/page_alloc.c

+17 −22
Original line number Diff line number Diff line
@@ -2217,7 +2217,7 @@ static struct page * 
__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,

	struct zonelist *zonelist, enum zone_type high_zoneidx,

	nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,

	int migratetype, bool sync_migration,

	int migratetype, enum migrate_mode mode,

	bool *contended_compaction, bool *deferred_compaction,

	unsigned long *did_some_progress)

{
@@ -2231,7 +2231,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, 


	current->flags |= PF_MEMALLOC;

	*did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,

						nodemask, sync_migration,

						nodemask, mode,

						contended_compaction);

	current->flags &= ~PF_MEMALLOC;
@@ -2264,7 +2264,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, 
		 * As async compaction considers a subset of pageblocks, only

		 * defer if the failure was a sync compaction failure.

		 */

		if (sync_migration)

		if (mode != MIGRATE_ASYNC)

			defer_compaction(preferred_zone, order);



		cond_resched();
@@ -2277,9 +2277,8 @@ static inline struct page * 
__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,

	struct zonelist *zonelist, enum zone_type high_zoneidx,

	nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,

	int migratetype, bool sync_migration,

	bool *contended_compaction, bool *deferred_compaction,

	unsigned long *did_some_progress)

	int migratetype, enum migrate_mode mode, bool *contended_compaction,

	bool *deferred_compaction, unsigned long *did_some_progress)

{

	return NULL;

}
@@ -2474,7 +2473,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, 
	int alloc_flags;

	unsigned long pages_reclaimed = 0;

	unsigned long did_some_progress;

	bool sync_migration = false;

	enum migrate_mode migration_mode = MIGRATE_ASYNC;

	bool deferred_compaction = false;

	bool contended_compaction = false;
@@ -2568,17 +2567,15 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, 
	 * Try direct compaction. The first pass is asynchronous. Subsequent

	 * attempts after direct reclaim are synchronous

	 */

	page = __alloc_pages_direct_compact(gfp_mask, order,

					zonelist, high_zoneidx,

					nodemask,

					alloc_flags, preferred_zone,

					migratetype, sync_migration,

					&contended_compaction,

	page = __alloc_pages_direct_compact(gfp_mask, order, zonelist,

					high_zoneidx, nodemask, alloc_flags,

					preferred_zone, migratetype,

					migration_mode, &contended_compaction,

					&deferred_compaction,

					&did_some_progress);

	if (page)

		goto got_pg;

	sync_migration = true;

	migration_mode = MIGRATE_SYNC_LIGHT;



	/*

	 * If compaction is deferred for high-order allocations, it is because
@@ -2653,12 +2650,10 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, 
		 * direct reclaim and reclaim/compaction depends on compaction

		 * being called after reclaim so call directly if necessary

		 */

		page = __alloc_pages_direct_compact(gfp_mask, order,

					zonelist, high_zoneidx,

					nodemask,

					alloc_flags, preferred_zone,

					migratetype, sync_migration,

					&contended_compaction,

		page = __alloc_pages_direct_compact(gfp_mask, order, zonelist,

					high_zoneidx, nodemask, alloc_flags,

					preferred_zone, migratetype,

					migration_mode, &contended_compaction,

					&deferred_compaction,

					&did_some_progress);

		if (page)
@@ -6218,7 +6213,7 @@ static int __alloc_contig_migrate_range(struct compact_control *cc, 
		cc->nr_migratepages -= nr_reclaimed;



		ret = migrate_pages(&cc->migratepages, alloc_migrate_target,

				    NULL, 0, MIGRATE_SYNC, MR_CMA);

				    NULL, 0, cc->mode, MR_CMA);

	}

	if (ret < 0) {

		putback_movable_pages(&cc->migratepages);
@@ -6257,7 +6252,7 @@ int alloc_contig_range(unsigned long start, unsigned long end, 
		.nr_migratepages = 0,

		.order = -1,

		.zone = page_zone(pfn_to_page(start)),

		.sync = true,

		.mode = MIGRATE_SYNC,

		.ignore_skip_hint = true,

	};

	INIT_LIST_HEAD(&cc.migratepages);