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    Subject[PATCH 3.18 056/134] perf tools: Handle TOPOLOGY headers with no CPU
    Date
    3.18-stable review patch.  If anyone has any objections, please let me know.

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

    [ Upstream commit 1497e804d1a6e2bd9107ddf64b0310449f4673eb ]

    This patch fixes an issue in cpumap.c when used with the TOPOLOGY
    header. In some configurations, some NUMA nodes may have no CPU (empty
    cpulist). Yet a cpumap map must be created otherwise perf abort with an
    error. This patch handles this case by creating a dummy map.

    Before:

    $ perf record -o - -e cycles noploop 2 | perf script -i -
    0x6e8 [0x6c]: failed to process type: 80

    After:

    $ perf record -o - -e cycles noploop 2 | perf script -i -
    noploop for 2 seconds

    Signed-off-by: Stephane Eranian <eranian@google.com>
    Acked-by: Jiri Olsa <jolsa@kernel.org>
    Cc: Andi Kleen <ak@linux.intel.com>
    Cc: Kan Liang <kan.liang@linux.intel.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Link: http://lkml.kernel.org/r/1547885559-1657-1-git-send-email-eranian@google.com
    Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    tools/perf/util/cpumap.c | 11 +++++++++--
    1 file changed, 9 insertions(+), 2 deletions(-)

    diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
    index c4e55b71010c..2ccfeb78fd5d 100644
    --- a/tools/perf/util/cpumap.c
    +++ b/tools/perf/util/cpumap.c
    @@ -121,7 +121,12 @@ struct cpu_map *cpu_map__new(const char *cpu_list)
    if (!cpu_list)
    return cpu_map__read_all_cpu_map();

    - if (!isdigit(*cpu_list))
    + /*
    + * must handle the case of empty cpumap to cover
    + * TOPOLOGY header for NUMA nodes with no CPU
    + * ( e.g., because of CPU hotplug)
    + */
    + if (!isdigit(*cpu_list) && *cpu_list != '\0')
    goto out;

    while (isdigit(*cpu_list)) {
    @@ -168,8 +173,10 @@ struct cpu_map *cpu_map__new(const char *cpu_list)

    if (nr_cpus > 0)
    cpus = cpu_map__trim_new(nr_cpus, tmp_cpus);
    - else
    + else if (*cpu_list != '\0')
    cpus = cpu_map__default_new();
    + else
    + cpus = cpu_map__dummy_new();
    invalid:
    free(tmp_cpus);
    out:
    --
    2.19.1


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