Commit 57054651 authored by Johannes Weiner's avatar Johannes Weiner Committed by Linus Torvalds
Browse files

mm: clean up zone flags 



Page reclaim tests zone_is_reclaim_dirty(), but the site that actually
sets this state does zone_set_flag(zone, ZONE_TAIL_LRU_DIRTY), sending the
reader through layers indirection just to track down a simple bit.

Remove all zone flag wrappers and just use bitops against zone->flags
directly.  It's just as readable and the lines are barely any longer.

Also rename ZONE_TAIL_LRU_DIRTY to ZONE_DIRTY to match ZONE_WRITEBACK, and
remove the zone_flags_t typedef.

Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Acked-by: default avatarMel Gorman <mgorman@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7c809968

include/linux/mmzone.h

+3 −48
Original line number Diff line number Diff line
@@ -521,13 +521,13 @@ struct zone { 
	atomic_long_t		vm_stat[NR_VM_ZONE_STAT_ITEMS];

} ____cacheline_internodealigned_in_smp;



typedef enum {

enum zone_flags {

	ZONE_RECLAIM_LOCKED,		/* prevents concurrent reclaim */

	ZONE_OOM_LOCKED,		/* zone is in OOM killer zonelist */

	ZONE_CONGESTED,			/* zone has many dirty pages backed by

					 * a congested BDI

					 */

	ZONE_TAIL_LRU_DIRTY,		/* reclaim scanning has recently found

	ZONE_DIRTY,			/* reclaim scanning has recently found

					 * many dirty file pages at the tail

					 * of the LRU.

					 */
@@ -535,52 +535,7 @@ typedef enum { 
					 * many pages under writeback

					 */

	ZONE_FAIR_DEPLETED,		/* fair zone policy batch depleted */

} zone_flags_t;



static inline void zone_set_flag(struct zone *zone, zone_flags_t flag)

{

	set_bit(flag, &zone->flags);

}



static inline int zone_test_and_set_flag(struct zone *zone, zone_flags_t flag)

{

	return test_and_set_bit(flag, &zone->flags);

}



static inline void zone_clear_flag(struct zone *zone, zone_flags_t flag)

{

	clear_bit(flag, &zone->flags);

}



static inline int zone_is_reclaim_congested(const struct zone *zone)

{

	return test_bit(ZONE_CONGESTED, &zone->flags);

}



static inline int zone_is_reclaim_dirty(const struct zone *zone)

{

	return test_bit(ZONE_TAIL_LRU_DIRTY, &zone->flags);

}



static inline int zone_is_reclaim_writeback(const struct zone *zone)

{

	return test_bit(ZONE_WRITEBACK, &zone->flags);

}



static inline int zone_is_reclaim_locked(const struct zone *zone)

{

	return test_bit(ZONE_RECLAIM_LOCKED, &zone->flags);

}



static inline int zone_is_fair_depleted(const struct zone *zone)

{

	return test_bit(ZONE_FAIR_DEPLETED, &zone->flags);

}



static inline int zone_is_oom_locked(const struct zone *zone)

{

	return test_bit(ZONE_OOM_LOCKED, &zone->flags);

}

};



static inline unsigned long zone_end_pfn(const struct zone *zone)

{

mm/backing-dev.c

+1 −1
Original line number Diff line number Diff line
@@ -631,7 +631,7 @@ long wait_iff_congested(struct zone *zone, int sync, long timeout) 
	 * of sleeping on the congestion queue

	 */

	if (atomic_read(&nr_bdi_congested[sync]) == 0 ||

			!zone_is_reclaim_congested(zone)) {

	    !test_bit(ZONE_CONGESTED, &zone->flags)) {

		cond_resched();



		/* In case we scheduled, work out time remaining */

mm/oom_kill.c

+3 −3
Original line number Diff line number Diff line
@@ -565,7 +565,7 @@ bool oom_zonelist_trylock(struct zonelist *zonelist, gfp_t gfp_mask) 


	spin_lock(&zone_scan_lock);

	for_each_zone_zonelist(zone, z, zonelist, gfp_zone(gfp_mask))

		if (zone_is_oom_locked(zone)) {

		if (test_bit(ZONE_OOM_LOCKED, &zone->flags)) {

			ret = false;

			goto out;

		}
@@ -575,7 +575,7 @@ bool oom_zonelist_trylock(struct zonelist *zonelist, gfp_t gfp_mask) 
	 * call to oom_zonelist_trylock() doesn't succeed when it shouldn't.

	 */

	for_each_zone_zonelist(zone, z, zonelist, gfp_zone(gfp_mask))

		zone_set_flag(zone, ZONE_OOM_LOCKED);

		set_bit(ZONE_OOM_LOCKED, &zone->flags);



out:

	spin_unlock(&zone_scan_lock);
@@ -594,7 +594,7 @@ void oom_zonelist_unlock(struct zonelist *zonelist, gfp_t gfp_mask) 


	spin_lock(&zone_scan_lock);

	for_each_zone_zonelist(zone, z, zonelist, gfp_zone(gfp_mask))

		zone_clear_flag(zone, ZONE_OOM_LOCKED);

		clear_bit(ZONE_OOM_LOCKED, &zone->flags);

	spin_unlock(&zone_scan_lock);

}

mm/page_alloc.c

+4 −4
Original line number Diff line number Diff line
@@ -1614,8 +1614,8 @@ again: 


	__mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));

	if (atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]) <= 0 &&

	    !zone_is_fair_depleted(zone))

		zone_set_flag(zone, ZONE_FAIR_DEPLETED);

	    !test_bit(ZONE_FAIR_DEPLETED, &zone->flags))

		set_bit(ZONE_FAIR_DEPLETED, &zone->flags);



	__count_zone_vm_events(PGALLOC, zone, 1 << order);

	zone_statistics(preferred_zone, zone, gfp_flags);
@@ -1935,7 +1935,7 @@ static void reset_alloc_batches(struct zone *preferred_zone) 
		mod_zone_page_state(zone, NR_ALLOC_BATCH,

			high_wmark_pages(zone) - low_wmark_pages(zone) -

			atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));

		zone_clear_flag(zone, ZONE_FAIR_DEPLETED);

		clear_bit(ZONE_FAIR_DEPLETED, &zone->flags);

	} while (zone++ != preferred_zone);

}
@@ -1986,7 +1986,7 @@ zonelist_scan: 
		if (alloc_flags & ALLOC_FAIR) {

			if (!zone_local(preferred_zone, zone))

				break;

			if (zone_is_fair_depleted(zone)) {

			if (test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) {

				nr_fair_skipped++;

				continue;

			}

mm/vmscan.c

+14 −14
Original line number Diff line number Diff line
@@ -920,7 +920,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, 
			/* Case 1 above */

			if (current_is_kswapd() &&

			    PageReclaim(page) &&

			    zone_is_reclaim_writeback(zone)) {

			    test_bit(ZONE_WRITEBACK, &zone->flags)) {

				nr_immediate++;

				goto keep_locked;
@@ -1002,7 +1002,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, 
			 */

			if (page_is_file_cache(page) &&

					(!current_is_kswapd() ||

					 !zone_is_reclaim_dirty(zone))) {

					 !test_bit(ZONE_DIRTY, &zone->flags))) {

				/*

				 * Immediately reclaim when written back.

				 * Similar in principal to deactivate_page()
@@ -1563,7 +1563,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, 
	 * are encountered in the nr_immediate check below.

	 */

	if (nr_writeback && nr_writeback == nr_taken)

		zone_set_flag(zone, ZONE_WRITEBACK);

		set_bit(ZONE_WRITEBACK, &zone->flags);



	/*

	 * memcg will stall in page writeback so only consider forcibly
@@ -1575,16 +1575,16 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, 
		 * backed by a congested BDI and wait_iff_congested will stall.

		 */

		if (nr_dirty && nr_dirty == nr_congested)

			zone_set_flag(zone, ZONE_CONGESTED);

			set_bit(ZONE_CONGESTED, &zone->flags);



		/*

		 * If dirty pages are scanned that are not queued for IO, it

		 * implies that flushers are not keeping up. In this case, flag

		 * the zone ZONE_TAIL_LRU_DIRTY and kswapd will start writing

		 * pages from reclaim context.

		 * the zone ZONE_DIRTY and kswapd will start writing pages from

		 * reclaim context.

		 */

		if (nr_unqueued_dirty == nr_taken)

			zone_set_flag(zone, ZONE_TAIL_LRU_DIRTY);

			set_bit(ZONE_DIRTY, &zone->flags);



		/*

		 * If kswapd scans pages marked marked for immediate
@@ -2984,7 +2984,7 @@ static bool kswapd_shrink_zone(struct zone *zone, 
	/* Account for the number of pages attempted to reclaim */

	*nr_attempted += sc->nr_to_reclaim;



	zone_clear_flag(zone, ZONE_WRITEBACK);

	clear_bit(ZONE_WRITEBACK, &zone->flags);



	/*

	 * If a zone reaches its high watermark, consider it to be no longer
@@ -2994,8 +2994,8 @@ static bool kswapd_shrink_zone(struct zone *zone, 
	 */

	if (zone_reclaimable(zone) &&

	    zone_balanced(zone, testorder, 0, classzone_idx)) {

		zone_clear_flag(zone, ZONE_CONGESTED);

		zone_clear_flag(zone, ZONE_TAIL_LRU_DIRTY);

		clear_bit(ZONE_CONGESTED, &zone->flags);

		clear_bit(ZONE_DIRTY, &zone->flags);

	}



	return sc->nr_scanned >= sc->nr_to_reclaim;
@@ -3086,8 +3086,8 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order, 
				 * If balanced, clear the dirty and congested

				 * flags

				 */

				zone_clear_flag(zone, ZONE_CONGESTED);

				zone_clear_flag(zone, ZONE_TAIL_LRU_DIRTY);

				clear_bit(ZONE_CONGESTED, &zone->flags);

				clear_bit(ZONE_DIRTY, &zone->flags);

			}

		}
@@ -3714,11 +3714,11 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) 
	if (node_state(node_id, N_CPU) && node_id != numa_node_id())

		return ZONE_RECLAIM_NOSCAN;



	if (zone_test_and_set_flag(zone, ZONE_RECLAIM_LOCKED))

	if (test_and_set_bit(ZONE_RECLAIM_LOCKED, &zone->flags))

		return ZONE_RECLAIM_NOSCAN;



	ret = __zone_reclaim(zone, gfp_mask, order);

	zone_clear_flag(zone, ZONE_RECLAIM_LOCKED);

	clear_bit(ZONE_RECLAIM_LOCKED, &zone->flags);



	if (!ret)

		count_vm_event(PGSCAN_ZONE_RECLAIM_FAILED);

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