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/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 020d871..34e255f 100644 (file)
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -69,8 +69,8 @@ OPTIONS
        Output file name.
 
 -i::
---inherit::
-       Child tasks inherit counters.
+--no-inherit::
+       Child tasks do not inherit counters.
 -F::
 --freq=::
        Profile at this frequency.

diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index 484080d..2cab8e8 100644 (file)
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -31,8 +31,8 @@ OPTIONS
         hexadecimal event descriptor.
 
 -i::
---inherit::
-        child tasks inherit counters
+--no-inherit::
+        child tasks do not inherit counters
 -p::
 --pid=<pid>::
         stat events on existing pid

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 6b77b28..0f467cf 100644 (file)
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -54,7 +54,7 @@ static pid_t                  target_tid                      =     -1;
 static pid_t                   *all_tids                       =      NULL;
 static int                     thread_num                      =      0;
 static pid_t                   child_pid                       =     -1;
-static bool                    inherit                         =   true;
+static bool                    no_inherit                      =  false;
 static enum write_mode_t       write_mode                      = WRITE_FORCE;
 static bool                    call_graph                      =  false;
 static bool                    inherit_stat                    =  false;
@@ -298,8 +298,8 @@ static void create_counter(int counter, int cpu)
 
        attr->mmap              = track;
        attr->comm              = track;
-       attr->inherit           = inherit;
-       if (target_pid == -1 && !system_wide) {
+       attr->inherit           = !no_inherit;
+       if (target_pid == -1 && target_tid == -1 && !system_wide) {
                attr->disabled = 1;
                attr->enable_on_exec = 1;
        }
@@ -641,7 +641,7 @@ static int __cmd_record(int argc, const char **argv)
                close(child_ready_pipe[0]);
        }
 
-       if ((!system_wide && !inherit) || profile_cpu != -1) {
+       if ((!system_wide && no_inherit) || profile_cpu != -1) {
                open_counters(profile_cpu);
        } else {
                nr_cpus = read_cpu_map();
@@ -821,8 +821,8 @@ static const struct option options[] = {
                    "event period to sample"),
        OPT_STRING('o', "output", &output_name, "file",
                    "output file name"),
-       OPT_BOOLEAN('i', "inherit", &inherit,
-                   "child tasks inherit counters"),
+       OPT_BOOLEAN('i', "no-inherit", &no_inherit,
+                   "child tasks do not inherit counters"),
        OPT_INTEGER('F', "freq", &user_freq,
                    "profile at this frequency"),
        OPT_INTEGER('m', "mmap-pages", &mmap_pages,

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index e619ac8..ff8c413 100644 (file)
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -72,7 +72,7 @@ static unsigned int           nr_cpus                         =  0;
 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 @@ static int create_perf_stat_counter(int counter)
                                ++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 @@ static const struct option options[] = {
        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,