• Namhyung Kim's avatar
    perf arm-spe: Track task context switch for cpu-mode events · 9dc9855f
    Namhyung Kim authored
    When perf report synthesize events from ARM SPE data, it refers to
    current cpu, pid and tid in the machine.  But there's no place to set
    them in the ARM SPE decoder.  I'm seeing all pid/tid is set to -1 and
    user symbols are not resolved in the output.
    
      # perf record -a -e arm_spe_0/ts_enable=1/ sleep 1
    
      # perf report -q | head
         8.77%     8.77%  :-1      [kernel.kallsyms]  [k] format_decode
         7.02%     7.02%  :-1      [kernel.kallsyms]  [k] seq_printf
         7.02%     7.02%  :-1      [unknown]          [.] 0x0000ffff9f687c34
         5.26%     5.26%  :-1      [kernel.kallsyms]  [k] vsnprintf
         3.51%     3.51%  :-1      [kernel.kallsyms]  [k] string
         3.51%     3.51%  :-1      [unknown]          [.] 0x0000ffff9f66ae20
         3.51%     3.51%  :-1      [unknown]          [.] 0x0000ffff9f670b3c
         3.51%     3.51%  :-1      [unknown]          [.] 0x0000ffff9f67c040
         1.75%     1.75%  :-1      [kernel.kallsyms]  [k] ___cache_free
         1.75%     1.75%  :-1      [kernel.kallsyms]  [k] __count_memcg_events
    
    Like Intel PT, add context switch records to track task info.  As ARM
    SPE support was added later than PERF_RECORD_SWITCH_CPU_WIDE, I think
    we can safely set the attr.context_switch bit and use it.
    Reviewed-by: default avatarLeo Yan <leo.yan@linaro.org>
    Signed-off-by: default avatarGerman Gomez <german.gomez@arm.com>
    Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
    Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
    Cc: Jiri Olsa <jolsa@redhat.com>
    Cc: John Garry <john.garry@huawei.com>
    Cc: Mark Rutland <mark.rutland@arm.com>
    Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
    Cc: Will Deacon <will@kernel.org>
    Cc: linux-arm-kernel@lists.infradead.org
    Link: https://lore.kernel.org/r/20211111133625.193568-2-german.gomez@arm.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    9dc9855f
arm-spe.c 13.8 KB