From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753687AbcD0PiR (ORCPT ); Wed, 27 Apr 2016 11:38:17 -0400 Received: from terminus.zytor.com ([198.137.202.10]:51376 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753490AbcD0PiP (ORCPT ); Wed, 27 Apr 2016 11:38:15 -0400 Date: Wed, 27 Apr 2016 08:37:54 -0700 From: tip-bot for Arnaldo Carvalho de Melo Message-ID: Cc: adrian.hunter@intel.com, tglx@linutronix.de, bp@suse.de, namhyung@kernel.org, acme@redhat.com, wangnan0@huawei.com, dsahern@gmail.com, milian.wolff@kdab.com, hpa@zytor.com, linux-kernel@vger.kernel.org, mingo@kernel.org, jolsa@kernel.org Reply-To: hpa@zytor.com, linux-kernel@vger.kernel.org, jolsa@kernel.org, mingo@kernel.org, acme@redhat.com, milian.wolff@kdab.com, dsahern@gmail.com, wangnan0@huawei.com, bp@suse.de, namhyung@kernel.org, adrian.hunter@intel.com, tglx@linutronix.de To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf trace: Read thread's COMM from /proc when not set Git-Commit-ID: 073e5fca53d30ffe9e2fc637a001c78b2cdca7dd X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 073e5fca53d30ffe9e2fc637a001c78b2cdca7dd Gitweb: http://git.kernel.org/tip/073e5fca53d30ffe9e2fc637a001c78b2cdca7dd Author: Arnaldo Carvalho de Melo AuthorDate: Tue, 26 Apr 2016 12:33:46 -0300 Committer: Arnaldo Carvalho de Melo CommitDate: Tue, 26 Apr 2016 13:15:00 -0300 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 Cc: Borislav Petkov Cc: David Ahern Cc: Jiri Olsa Cc: Milian Wolff Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-ioeps6dlwst17d6oozc9shtk@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/trace/beauty/pid.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/tools/perf/trace/beauty/pid.c b/tools/perf/trace/beauty/pid.c index 111ae08..07486ea 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));