mm, vmstat: Remove spurious WARN() during zoneinfo print

After commit 5b61b7818a88 ("mm, vmstat: print non-populated zones in
zoneinfo"), /proc/zoneinfo will show unpopulated zones.

A memoryless node, having no populated zones at all, was previously
ignored, but will now trigger the WARN() in is_zone_first_populated().

Remove this warning, as its only purpose was to warn of a situation that
has since been enabled.

Aside: The "per-node stats" are still printed under the first populated
zone, but that's not necessarily the first stanza any more.  I'm not
sure which criteria is more important with regard to not breaking
parsers, but it looks a little weird to the eye.

Fixes:  5b61b7818a88 ("mm, vmstat: print node-based stats in zoneinfo file")
Link: http://lkml.kernel.org/r/1493854905-10918-1-git-send-email-arbab@linux.vnet.ibm.com
Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.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 f5fa1bd1eb1656cb4e608bd301c83e92f66ac3b2..76f73670200ac1d34b5f17388df8356fadffaf71 100644 (file)
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1359,8 +1359,6 @@ static bool is_zone_first_populated(pg_data_t *pgdat, struct zone *zone)
                        return zone == compare;
        }
 
-       /* The zone must be somewhere! */
-       WARN_ON_ONCE(1);
        return false;
 }