Commit 727c080f authored by Vinayak Menon's avatar Vinayak Menon Committed by Linus Torvalds
Browse files

mm: avoid taking zone lock in pagetypeinfo_showmixed() 

pagetypeinfo_showmixedcount_print is found to take a lot of time to
complete and it does this holding the zone lock and disabling
interrupts.  In some cases it is found to take more than a second (On a
2.4GHz,8Gb RAM,arm64 cpu).

Avoid taking the zone lock similar to what is done by read_page_owner,
which means possibility of inaccurate results.

Link: http://lkml.kernel.org/r/1498045643-12257-1-git-send-email-vinmenon@codeaurora.org


Signed-off-by: default avatarVinayak Menon <vinmenon@codeaurora.org>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: zhongjiang <zhongjiang@huawei.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ef77ba5c

mm/page_owner.c

+5 −1
Original line number Diff line number Diff line
@@ -281,7 +281,11 @@ void pagetypeinfo_showmixedcount_print(struct seq_file *m, 
				continue;



			if (PageBuddy(page)) {

				pfn += (1UL << page_order(page)) - 1;

				unsigned long freepage_order;



				freepage_order = page_order_unsafe(page);

				if (freepage_order < MAX_ORDER)

					pfn += (1UL << freepage_order) - 1;

				continue;

			}

mm/vmstat.c

+14 −10
Original line number Diff line number Diff line
@@ -1130,7 +1130,7 @@ static void frag_stop(struct seq_file *m, void *arg) 
 * If @assert_populated is true, only use callback for zones that are populated.

 */

static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,

		bool assert_populated,

		bool assert_populated, bool nolock,

		void (*print)(struct seq_file *m, pg_data_t *, struct zone *))

{

	struct zone *zone;
@@ -1141,8 +1141,10 @@ static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat, 
		if (assert_populated && !populated_zone(zone))

			continue;



		if (!nolock)

			spin_lock_irqsave(&zone->lock, flags);

		print(m, pgdat, zone);

		if (!nolock)

			spin_unlock_irqrestore(&zone->lock, flags);

	}

}
@@ -1166,7 +1168,7 @@ static void frag_show_print(struct seq_file *m, pg_data_t *pgdat, 
static int frag_show(struct seq_file *m, void *arg)

{

	pg_data_t *pgdat = (pg_data_t *)arg;

	walk_zones_in_node(m, pgdat, true, frag_show_print);

	walk_zones_in_node(m, pgdat, true, false, frag_show_print);

	return 0;

}
@@ -1207,7 +1209,7 @@ static int pagetypeinfo_showfree(struct seq_file *m, void *arg) 
		seq_printf(m, "%6d ", order);

	seq_putc(m, '\n');



	walk_zones_in_node(m, pgdat, true, pagetypeinfo_showfree_print);

	walk_zones_in_node(m, pgdat, true, false, pagetypeinfo_showfree_print);



	return 0;

}
@@ -1258,7 +1260,8 @@ static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg) 
	for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)

		seq_printf(m, "%12s ", migratetype_names[mtype]);

	seq_putc(m, '\n');

	walk_zones_in_node(m, pgdat, true, pagetypeinfo_showblockcount_print);

	walk_zones_in_node(m, pgdat, true, false,

		pagetypeinfo_showblockcount_print);



	return 0;

}
@@ -1284,7 +1287,8 @@ static void pagetypeinfo_showmixedcount(struct seq_file *m, pg_data_t *pgdat) 
		seq_printf(m, "%12s ", migratetype_names[mtype]);

	seq_putc(m, '\n');



	walk_zones_in_node(m, pgdat, true, pagetypeinfo_showmixedcount_print);

	walk_zones_in_node(m, pgdat, true, true,

		pagetypeinfo_showmixedcount_print);

#endif /* CONFIG_PAGE_OWNER */

}
@@ -1446,7 +1450,7 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat, 
static int zoneinfo_show(struct seq_file *m, void *arg)

{

	pg_data_t *pgdat = (pg_data_t *)arg;

	walk_zones_in_node(m, pgdat, false, zoneinfo_show_print);

	walk_zones_in_node(m, pgdat, false, false, zoneinfo_show_print);

	return 0;

}
@@ -1852,7 +1856,7 @@ static int unusable_show(struct seq_file *m, void *arg) 
	if (!node_state(pgdat->node_id, N_MEMORY))

		return 0;



	walk_zones_in_node(m, pgdat, true, unusable_show_print);

	walk_zones_in_node(m, pgdat, true, false, unusable_show_print);



	return 0;

}
@@ -1904,7 +1908,7 @@ static int extfrag_show(struct seq_file *m, void *arg) 
{

	pg_data_t *pgdat = (pg_data_t *)arg;



	walk_zones_in_node(m, pgdat, true, extfrag_show_print);

	walk_zones_in_node(m, pgdat, true, false, extfrag_show_print);



	return 0;

}

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