[tip:perfcounters/core] perf_counter tools: Propagate signals properly

tip-bot for Peter Zijlstra
2009-06-10T15:43:46Z

Commit-ID: f7b7c26e01e51fe46097e11f179dc71ce7950084
Gitweb: http://git.kernel.org/tip/f7b7c26e01e51fe46097e11f179dc71ce7950084
Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Wed, 10 Jun 2009 15:55:59 +0200
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 10 Jun 2009 16:55:27 +0200

perf_counter tools: Propagate signals properly

Currently report and stat catch SIGINT (and others) without altering
their exit state. This means that things like:

while :; do perf stat ./foo ; done

Loops become hard-to-interrupt, because bash never sees perf terminate
due to interruption. Fix this.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

---
tools/perf/builtin-record.c | 12 ++++++++++++
tools/perf/builtin-stat.c | 13 +++++++++++++
2 files changed, 25 insertions(+), 0 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index a5698ad..c10553c 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -169,10 +169,21 @@ static void mmap_read(struct mmap_data *md)
}

static volatile int done = 0;
+static volatile int signr = -1;

static void sig_handler(int sig)
{
done = 1;
+ signr = sig;
+}
+
+static void sig_atexit(void)
+{
+ if (signr == -1)
+ return;
+
+ signal(signr, SIG_DFL);
+ kill(getpid(), signr);
}

static void pid_synthesize_comm_event(pid_t pid, int full)
@@ -459,6 +470,7 @@ static int __cmd_record(int argc, const char **argv)
} else for (i = 0; i < nr_cpus; i++)
open_counters(i, target_pid);

+ atexit(sig_atexit);
signal(SIGCHLD, sig_handler);
signal(SIGINT, sig_handler);

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 8085509..6404906 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -296,8 +296,20 @@ static int do_perf_stat(int argc, const char **argv)
return 0;
}

+static volatile int signr = -1;
+
static void skip_signal(int signo)
{
+ signr = signo;
+}
+
+static void sig_atexit(void)
+{
+ if (signr == -1)
+ return;
+
+ signal(signr, SIG_DFL);
+ kill(getpid(), signr);
}

static const char * const stat_usage[] = {
@@ -345,6 +357,7 @@ int cmd_stat(int argc, const char **argv, const char *prefix)
* What we want is for Ctrl-C to work in the exec()-ed
* task, but being ignored by perf stat itself:
*/
+ atexit(sig_atexit);
signal(SIGINT, skip_signal);
signal(SIGALRM, skip_signal);
signal(SIGABRT, skip_signal);