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: Vinayak Menon <vinmenon@codeaurora.org>
Acked-by: Vlastimil 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 744ceae..9a4441b 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1130,7 +1130,7 @@
* 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;
@@ -1141,9 +1141,11 @@
if (assert_populated && !populated_zone(zone))
continue;
- spin_lock_irqsave(&zone->lock, flags);
+ if (!nolock)
+ spin_lock_irqsave(&zone->lock, flags);
print(m, pgdat, zone);
- spin_unlock_irqrestore(&zone->lock, flags);
+ if (!nolock)
+ spin_unlock_irqrestore(&zone->lock, flags);
}
}
#endif
@@ -1166,7 +1168,7 @@
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 @@
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 @@
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 @@
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 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 @@
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 @@
{
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;
}