Mathieu Poirier reports issue in commit ("73c0ca1e perf thread_map:
Enumerate all threads from /proc") that it has negative impact on 'perf
record --per-thread'. It has the effect of creating a kernel event for
each thread in the system for 'perf record --per-thread'.

Mathieu Poirier's patch ("perf util: Do not reuse target->per_thread flag")
can fix this issue by creating a new target->all_threads flag.

This patch is based on Mathieu Poirier's patch but it doesn't use a new
target->all_threads flag. This patch just uses 'target->per_thread &&
target->system_wide' as a condition to check for all threads case.
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org
Fixes: 73c0ca1e ("perf thread_map: Enumerate all threads from /proc")
Link: http://lkml.kernel.org/r/1518467557-18505-3-git-send-email-mathieu.poirier@linaro.orgSigned-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
[Fixed checkpatch warning about line over 80 characters]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>