perf tools: change event inheritance logic in stat and record
By default, event inheritance across fork and pthread_create was on but the -i
option of stat and record, which enabled inheritance, led to believe it was off
by default.
This patch fixes this logic by inverting the meaning of the -i option. By
default inheritance is on whether you attach to a process (-p), a thread (-t)
or start a process. If you pass -i, then you turn off inheritance. Turning off
inheritance if you don't need it, helps limit perf resource usage as well.
The patch also fixes perf stat -t xxxx and perf record -t xxxx which did not
start the counters.
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <4bea9d2f.d60ce30a.0b5b.08e1@mx.google.com>
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index e619ac8..ff8c413 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -72,7 +72,7 @@
static int run_idx = 0;
static int run_count = 1;
-static bool inherit = true;
+static bool no_inherit = false;
static bool scale = true;
static pid_t target_pid = -1;
static pid_t target_tid = -1;
@@ -167,8 +167,8 @@
++ncreated;
}
} else {
- attr->inherit = inherit;
- if (target_pid == -1) {
+ attr->inherit = !no_inherit;
+ if (target_pid == -1 && target_tid == -1) {
attr->disabled = 1;
attr->enable_on_exec = 1;
}
@@ -518,8 +518,8 @@
OPT_CALLBACK('e', "event", NULL, "event",
"event selector. use 'perf list' to list available events",
parse_events),
- OPT_BOOLEAN('i', "inherit", &inherit,
- "child tasks inherit counters"),
+ OPT_BOOLEAN('i', "no-inherit", &no_inherit,
+ "child tasks do not inherit counters"),
OPT_INTEGER('p', "pid", &target_pid,
"stat events on existing process id"),
OPT_INTEGER('t', "tid", &target_tid,