releases/3.18.137/perf-tools-handle-topology-headers-with-no-cpu.patch

   1 From d06e8eda25bdbe088b2876d40f416ba4f20b4d49 Mon Sep 17 00:00:00 2001
   2 From: Stephane Eranian <eranian@google.com>
   3 Date: Sat, 19 Jan 2019 00:12:39 -0800
   4 Subject: perf tools: Handle TOPOLOGY headers with no CPU
   5
   6 [ Upstream commit 1497e804d1a6e2bd9107ddf64b0310449f4673eb ]
   7
   8 This patch fixes an issue in cpumap.c when used with the TOPOLOGY
   9 header. In some configurations, some NUMA nodes may have no CPU (empty
  10 cpulist). Yet a cpumap map must be created otherwise perf abort with an
  11 error. This patch handles this case by creating a dummy map.
  12
  13   Before:
  14
  15   $ perf record -o - -e cycles noploop 2 | perf script -i -
  16   0x6e8 [0x6c]: failed to process type: 80
  17
  18   After:
  19
  20   $ perf record -o - -e cycles noploop 2 | perf script -i -
  21   noploop for 2 seconds
  22
  23 Signed-off-by: Stephane Eranian <eranian@google.com>
  24 Acked-by: Jiri Olsa <jolsa@kernel.org>
  25 Cc: Andi Kleen <ak@linux.intel.com>
  26 Cc: Kan Liang <kan.liang@linux.intel.com>
  27 Cc: Peter Zijlstra <peterz@infradead.org>
  28 Link: http://lkml.kernel.org/r/1547885559-1657-1-git-send-email-eranian@google.com
  29 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
  30 Signed-off-by: Sasha Levin <sashal@kernel.org>
  31 ---
  32  tools/perf/util/cpumap.c | 11 +++++++++--
  33  1 file changed, 9 insertions(+), 2 deletions(-)
  34
  35 diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
  36 index c4e55b71010c..2ccfeb78fd5d 100644
  37 --- a/tools/perf/util/cpumap.c
  38 +++ b/tools/perf/util/cpumap.c
  39 @@ -121,7 +121,12 @@ struct cpu_map *cpu_map__new(const char *cpu_list)
  40         if (!cpu_list)
  41                 return cpu_map__read_all_cpu_map();
  42
  43 -       if (!isdigit(*cpu_list))
  44 +       /*
  45 +        * must handle the case of empty cpumap to cover
  46 +        * TOPOLOGY header for NUMA nodes with no CPU
  47 +        * ( e.g., because of CPU hotplug)
  48 +        */
  49 +       if (!isdigit(*cpu_list) && *cpu_list != '\0')
  50                 goto out;
  51
  52         while (isdigit(*cpu_list)) {
  53 @@ -168,8 +173,10 @@ struct cpu_map *cpu_map__new(const char *cpu_list)
  54
  55         if (nr_cpus > 0)
  56                 cpus = cpu_map__trim_new(nr_cpus, tmp_cpus);
  57 -       else
  58 +       else if (*cpu_list != '\0')
  59                 cpus = cpu_map__default_new();
  60 +       else
  61 +               cpus = cpu_map__dummy_new();
  62  invalid:
  63         free(tmp_cpus);
  64  out:
  65 --
  66 2.19.1
  67