[PATCH 41/43] perf trace: Handle multiple threads better wrt syscalls being intermixed

Arnaldo Carvalho de Melo
2015-02-13T20:53:04Z

From: Arnaldo Carvalho de Melo <acme@redhat.com>

$ trace time taskset -c 0 usleep 1
0.845 ( 0.021 ms): time/16722 wait4(upid: 4294967295, stat_addr: 0x7fff17f443d4, ru: 0x7fff17f44438 ) ...
0.865 ( 0.008 ms): time/16723 execve(arg0: 140733595272004, arg1: 140733595272720, arg2: 140733595272768, arg3: 139755107218496, arg4: 7307199665339051828, arg5: 3) = -2
2.395 ( 1.523 ms): taskset/16723 execve(arg0: 140733595272013, arg1: 140733595272720, arg2: 140733595272768, arg3: 139755107218496, arg4: 7307199665339051828, arg5: 3) = 0
2.411 ( 0.002 ms): taskset/16723 brk( ) = 0x1915000
3.300 ( 0.058 ms): usleep/16723 nanosleep(rqtp: 0x7ffff4ada190 ) = 0
<SNIP>
3.305 ( 0.000 ms): usleep/16723 exit_group(
3.363 ( 2.539 ms): time/16722 ... [continued]: wait4()) = 16723
3.366 ( 0.001 ms): time/16722 rt_sigaction(sig: INT, act: 0x7fff17f44160, oact: 0x7fff17f44200, sigsetsize: 8) = 0

We we're not seeing this line:

0.845 ( 0.021 ms): time/16722 wait4(upid: 4294967295, stat_addr: 0x7fff17f443d4, ru: 0x7fff17f44438 ) ...

just the one when it finishes:

3.363 ( 2.539 ms): time/16722 ... [continued]: wait4()) = 16723

Still some issues left till we move to ordered_samples when multiple
CPUs/threads are involved...

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-zq9x30a1ky3djqewqn2v3ja3@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/builtin-trace.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 2bfb2343b798..feabd08ec90d 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -1220,6 +1220,7 @@ struct trace {
} syscalls;
struct record_opts opts;
struct machine *host;
+ struct thread *current;
u64 base_time;
FILE *output;
unsigned long nr_events;
@@ -1642,6 +1643,29 @@ static void thread__update_stats(struct thread_trace *ttrace,
update_stats(stats, duration);
}

+static int trace__printf_interrupted_entry(struct trace *trace, struct perf_sample *sample)
+{
+ struct thread_trace *ttrace;
+ u64 duration;
+ size_t printed;
+
+ if (trace->current == NULL)
+ return 0;
+
+ ttrace = thread__priv(trace->current);
+
+ if (!ttrace->entry_pending)
+ return 0;
+
+ duration = sample->time - ttrace->entry_time;
+
+ printed = trace__fprintf_entry_head(trace, trace->current, duration, sample->time, trace->output);
+ printed += fprintf(trace->output, "%-70s) ...\n", ttrace->entry_str);
+ ttrace->entry_pending = false;
+
+ return printed;
+}
+
static int trace__sys_enter(struct trace *trace, struct perf_evsel *evsel,
union perf_event *event __maybe_unused,
struct perf_sample *sample)
@@ -1673,6 +1697,8 @@ static int trace__sys_enter(struct trace *trace, struct perf_evsel *evsel,
return -1;
}

+ printed += trace__printf_interrupted_entry(trace, sample);
+
ttrace->entry_time = sample->time;
msg = ttrace->entry_str;
printed += scnprintf(msg + printed, 1024 - printed, "%s(", sc->name);
@@ -1688,6 +1714,8 @@ static int trace__sys_enter(struct trace *trace, struct perf_evsel *evsel,
} else
ttrace->entry_pending = true;

+ trace->current = thread;
+
return 0;
}

--
1.9.3