perf c2c: Fix c2c report for empty numa node

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@in.ibm.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190305152536.21035-2-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/builtin-c2c.c b/tools/perf/builtin-c2c.c
index 4272763a5e968fe00ff4024ee4504aa8749e8a7f..9e6cc868bdb4743418bff6eb91364986aceb8f3e 100644 (file)
--- a/tools/perf/builtin-c2c.c
+++ b/tools/perf/builtin-c2c.c
@@ -2056,6 +2056,12 @@ 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);
 
@@ -2064,8 +2070,6 @@ static int setup_nodes(struct perf_session *session)
 
                        cpu2node[map->map[cpu]] = node;
                }
-
-               nodes[node] = set;
        }
 
        setup_nodes_header();