perf trace: No need to set PERF_SAMPLE_IDENTIFIER explicitely

Since 75562573bab3 ("perf tools: Add support for
PERF_SAMPLE_IDENTIFIER") we don't need explicitely set
PERF_SAMPLE_IDENTIFIER, as perf_evlist__config() will do this for us,
i.e. when there are more than one evsel in an evlist, it will check if
some evsel has a sample_type different than the one on the first evsel
in the list, setting PERF_SAMPLE_IDENTIFIER in that case.

So, to simplify 'perf trace' codebase, ditch that check.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hendrick Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-12xq6orhwttee2tdtu96ucrp@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 71e64bd..e84816d 100644 (file)
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -2348,40 +2348,17 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
        perf_evlist__config(evlist, &trace->opts, NULL);
 
        if (callchain_param.enabled) {
-               bool use_identifier = false;
-
                if (trace->syscalls.events.sys_exit) {
                        perf_evsel__config_callchain(trace->syscalls.events.sys_exit,
                                                     &trace->opts, &callchain_param);
-                       use_identifier = true;
                }
 
                if (pgfault_maj) {
                        perf_evsel__config_callchain(pgfault_maj, &trace->opts, &callchain_param);
-                       use_identifier = true;
                }
 
                if (pgfault_min) {
                        perf_evsel__config_callchain(pgfault_min, &trace->opts, &callchain_param);
-                       use_identifier = true;
-               }
-
-               if (use_identifier) {
-                      /*
-                       * Now we have evsels with different sample_ids, use
-                       * PERF_SAMPLE_IDENTIFIER to map from sample to evsel
-                       * from a fixed position in each ring buffer record.
-                       *
-                       * As of this the changeset introducing this comment, this
-                       * isn't strictly needed, as the fields that can come before
-                       * PERF_SAMPLE_ID are all used, but we'll probably disable
-                       * some of those for things like copying the payload of
-                       * pointer syscall arguments, and for vfs_getname we don't
-                       * need PERF_SAMPLE_ADDR and PERF_SAMPLE_IP, so do this
-                       * here as a warning we need to use PERF_SAMPLE_IDENTIFIER.
-                       */
-                       perf_evlist__set_sample_bit(evlist, IDENTIFIER);
-                       perf_evlist__reset_sample_bit(evlist, ID);
                }
        }