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
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>
Git-commit: a94b5fd913ac55a32fe05dfba21eb6af0e539781
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
Change-Id: I11ec4a3a445d602e47fcc18a3e40480b74ad98af
[vinmenon@codeaurora.org: fix trivial merge conflicts]
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 42098b4..513c37a 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1122,6 +1122,7 @@
/* Walk all the zones in a node and print using a callback */
static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
+ bool nolock,
void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
{
struct zone *zone;
@@ -1132,9 +1133,11 @@
if (!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
@@ -1157,7 +1160,7 @@
static int frag_show(struct seq_file *m, void *arg)
{
pg_data_t *pgdat = (pg_data_t *)arg;
- walk_zones_in_node(m, pgdat, frag_show_print);
+ walk_zones_in_node(m, pgdat, false, frag_show_print);
return 0;
}
@@ -1198,7 +1201,7 @@
seq_printf(m, "%6d ", order);
seq_putc(m, '\n');
- walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);
+ walk_zones_in_node(m, pgdat, false, pagetypeinfo_showfree_print);
return 0;
}
@@ -1250,7 +1253,8 @@
for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
seq_printf(m, "%12s ", migratetype_names[mtype]);
seq_putc(m, '\n');
- walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);
+ walk_zones_in_node(m, pgdat, false,
+ pagetypeinfo_showblockcount_print);
return 0;
}
@@ -1276,7 +1280,8 @@
seq_printf(m, "%12s ", migratetype_names[mtype]);
seq_putc(m, '\n');
- walk_zones_in_node(m, pgdat, pagetypeinfo_showmixedcount_print);
+ walk_zones_in_node(m, pgdat, true,
+ pagetypeinfo_showmixedcount_print);
#endif /* CONFIG_PAGE_OWNER */
}
@@ -1433,7 +1438,7 @@
static int zoneinfo_show(struct seq_file *m, void *arg)
{
pg_data_t *pgdat = (pg_data_t *)arg;
- walk_zones_in_node(m, pgdat, zoneinfo_show_print);
+ walk_zones_in_node(m, pgdat, false, zoneinfo_show_print);
return 0;
}
@@ -1862,7 +1867,7 @@
if (!node_state(pgdat->node_id, N_MEMORY))
return 0;
- walk_zones_in_node(m, pgdat, unusable_show_print);
+ walk_zones_in_node(m, pgdat, false, unusable_show_print);
return 0;
}
@@ -1914,7 +1919,7 @@
{
pg_data_t *pgdat = (pg_data_t *)arg;
- walk_zones_in_node(m, pgdat, extfrag_show_print);
+ walk_zones_in_node(m, pgdat, false, extfrag_show_print);
return 0;
}