[PATCH 4.19 022/187] perf c2c: Fix c2c report for empty numa node

From: Greg Kroah-Hartman
Date: Thu Apr 04 2019 - 05:43:41 EST


4.19-stable review patch. If anyone has any objections, please let me know.

------------------

[ Upstream commit e34c940245437f36d2c492edd1f8237eff391064 ]

Ravi Bangoria reported that we fail with an empty NUMA node with the
following message:

$ lscpu
NUMA node0 CPU(s):
NUMA node1 CPU(s): 0-4

$ sudo ./perf c2c report
node/cpu topology bugFailed setup nodes

Fix this by detecting the empty node and keeping its CPU set empty.

Reported-by: Nageswara R Sastry <nasastry@xxxxxxxxxx>
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Tested-by: Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Jonas Rabenstein <jonas.rabenstein@xxxxxxxxxxxxxxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20190305152536.21035-2-jolsa@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
tools/perf/builtin-c2c.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-c2c.c b/tools/perf/builtin-c2c.c
index f3aa9d02a5ab..763c2edf52e7 100644
--- a/tools/perf/builtin-c2c.c
+++ b/tools/perf/builtin-c2c.c
@@ -2055,6 +2055,12 @@ static int setup_nodes(struct perf_session *session)
if (!set)
return -ENOMEM;

+ nodes[node] = set;
+
+ /* empty node, skip */
+ if (cpu_map__empty(map))
+ continue;
+
for (cpu = 0; cpu < map->nr; cpu++) {
set_bit(map->map[cpu], set);

@@ -2063,8 +2069,6 @@ static int setup_nodes(struct perf_session *session)

cpu2node[map->map[cpu]] = node;
}
-
- nodes[node] = set;
}

setup_nodes_header();
--
2.19.1