The patch titled
Subject: mm: avoid taking zone lock in pagetypeinfo_showmixed()
has been added to the -mm tree. Its filename is
mm-avoid-taking-zone-lock-in-pagetypeinfo_showmixed.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-avoid-taking-zone-lock-in-pagetypeinfo_showmixed.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-avoid-taking-zone-lock-in-pagetypeinfo_showmixed.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Vinayak Menon <vinmenon@xxxxxxxxxxxxxx>
Subject: 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@xxxxxxxxxxxxxx
Signed-off-by: Vinayak Menon <vinmenon@xxxxxxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: zhongjiang <zhongjiang@xxxxxxxxxx>
Cc: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
Cc: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_owner.c | 6 +++++-
mm/vmstat.c | 24 ++++++++++++++----------
2 files changed, 19 insertions(+), 11 deletions(-)
diff -puN mm/page_owner.c~mm-avoid-taking-zone-lock-in-pagetypeinfo_showmixed mm/page_owner.c
--- a/mm/page_owner.c~mm-avoid-taking-zone-lock-in-pagetypeinfo_showmixed
+++ a/mm/page_owner.c
@@ -281,7 +281,11 @@ void pagetypeinfo_showmixedcount_print(s
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;
}
diff -puN mm/vmstat.c~mm-avoid-taking-zone-lock-in-pagetypeinfo_showmixed mm/vmstat.c
--- a/mm/vmstat.c~mm-avoid-taking-zone-lock-in-pagetypeinfo_showmixed
+++ a/mm/vmstat.c
@@ -1130,7 +1130,7 @@ static void frag_stop(struct seq_file *m
* 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 @@ static void walk_zones_in_node(struct se
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 void frag_show_print(struct seq_f
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_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(s
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(
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 s
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
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
{
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;
}
_
Patches currently in -mm which might be from vinmenon@xxxxxxxxxxxxxx are
mm-avoid-taking-zone-lock-in-pagetypeinfo_showmixed.patch
mm-vmscan-do-not-pass-reclaimed-slab-to-vmpressure.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
