linux-kernel - [patch] mm, zoneinfo: print non-populated zones

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 2 Mar 2017 15:26:28 -0800 (PST)
From:   David Rientjes <rientjes@...gle.com>
To:     Andrew Morton <akpm@...ux-foundation.org>
cc:     Vlastimil Babka <vbabka@...e.cz>,
        Mel Gorman <mgorman@...hsingularity.net>,
        Johannes Weiner <hannes@...xchg.org>,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: [patch] mm, zoneinfo: print non-populated zones

Initscripts can use the information (protection levels) from
/proc/zoneinfo to configure vm.lowmem_reserve_ratio at boot.

vm.lowmem_reserve_ratio is an array of ratios for each configured zone on
the system.  If a zone is not populated on an arch, /proc/zoneinfo
suppresses its output.

This results in there not being a 1:1 mapping between the set of zones
emitted by /proc/zoneinfo and the zones configured by
vm.lowmem_reserve_ratio.

This patch shows statistics for non-populated zones in /proc/zoneinfo.
The zones exist and hold a spot in the vm.lowmem_reserve_ratio array.
Without this patch, it is not possible to determine which index in the
array controls which zone if one or more zones on the system are not
populated.

Remaining users of walk_zones_in_node() are unchanged.  Files such as
/proc/pagetypeinfo require certain zone data to be initialized properly
for display, which is not done for unpopulated zones.

Signed-off-by: David Rientjes <rientjes@...gle.com>
---
 mm/vmstat.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/mm/vmstat.c b/mm/vmstat.c
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1121,8 +1121,12 @@ static void frag_stop(struct seq_file *m, void *arg)
 {
 }
 
-/* Walk all the zones in a node and print using a callback */
+/*
+ * Walk zones in a node and print using a callback.
+ * If @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 populated,
 		void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
 {
 	struct zone *zone;
@@ -1130,7 +1134,7 @@ static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
 	unsigned long flags;
 
 	for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
-		if (!populated_zone(zone))
+		if (populated && !populated_zone(zone))
 			continue;
 
 		spin_lock_irqsave(&zone->lock, flags);
@@ -1158,7 +1162,7 @@ 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, frag_show_print);
+	walk_zones_in_node(m, pgdat, true, frag_show_print);
 	return 0;
 }
 
@@ -1199,7 +1203,7 @@ 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, pagetypeinfo_showfree_print);
+	walk_zones_in_node(m, pgdat, true, pagetypeinfo_showfree_print);
 
 	return 0;
 }
@@ -1251,7 +1255,7 @@ 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, pagetypeinfo_showblockcount_print);
+	walk_zones_in_node(m, pgdat, true, pagetypeinfo_showblockcount_print);
 
 	return 0;
 }
@@ -1277,7 +1281,7 @@ 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, pagetypeinfo_showmixedcount_print);
+	walk_zones_in_node(m, pgdat, true, pagetypeinfo_showmixedcount_print);
 #endif /* CONFIG_PAGE_OWNER */
 }
 
@@ -1434,7 +1438,7 @@ 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, zoneinfo_show_print);
+	walk_zones_in_node(m, pgdat, false, zoneinfo_show_print);
 	return 0;
 }
 
@@ -1853,7 +1857,7 @@ 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, unusable_show_print);
+	walk_zones_in_node(m, pgdat, true, unusable_show_print);
 
 	return 0;
 }
@@ -1905,7 +1909,7 @@ static int extfrag_show(struct seq_file *m, void *arg)
 {
 	pg_data_t *pgdat = (pg_data_t *)arg;
 
-	walk_zones_in_node(m, pgdat, extfrag_show_print);
+	walk_zones_in_node(m, pgdat, true, extfrag_show_print);
 
 	return 0;
 }