diff options
| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-04-26 12:33:46 -0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-04-26 13:15:00 -0300 |
| commit | 073e5fca53d30ffe9e2fc637a001c78b2cdca7dd (patch) | |
| tree | 883fad3a1e54ccc6e7503268437d6651f671d6fd /tools/perf/trace | |
| parent | 2f3027ac28bf6bc3ac7eb851eab06f2a38af5caa (diff) | |
perf trace: Read thread's COMM from /proc when not set
We get notifications for threads that gets created while we're tracing,
but for preexisting threads we may end not having synthesized them, like
when tracing a 'perf trace' session that will use '--pid' to trace some
other thread.
And besides we should probably stop synthesizing those records and
instead read thread information in a lazy way, i.e. just when we need,
like done in this patch:
Now the 'pid_t' argument in 'perf_event_open' gets translated to a COMM:
# perf trace -e perf_event_open perf stat -e cycles -p 31601
0.027 ( 0.027 ms): perf/23393 perf_event_open(attr_uptr: 0x2fdd0d8, pid: 31601 (abrt-dump-journ), cpu: -1, group_fd: -1, flags: FD_CLOEXEC)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= 3
^C
And in other syscalls containing pid_t without thread->comm_set at the
time of the formatting.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ioeps6dlwst17d6oozc9shtk@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/trace')
| -rw-r--r-- | tools/perf/trace/beauty/pid.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/tools/perf/trace/beauty/pid.c b/tools/perf/trace/beauty/pid.c index 111ae08d38f1..07486ea65ae3 100644 --- a/tools/perf/trace/beauty/pid.c +++ b/tools/perf/trace/beauty/pid.c @@ -3,9 +3,12 @@ static size_t syscall_arg__scnprintf_pid(char *bf, size_t size, struct syscall_a int pid = arg->val; struct trace *trace = arg->trace; size_t printed = scnprintf(bf, size, "%d", pid); - struct thread *thread = machine__find_thread(trace->host, pid, pid); + struct thread *thread = machine__findnew_thread(trace->host, pid, pid); if (thread != NULL) { + if (!thread->comm_set) + thread__set_comm_from_proc(thread); + if (thread->comm_set) printed += scnprintf(bf + printed, size - printed, " (%s)", thread__comm_str(thread)); |