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Commit 2e6cdf99 authored by Stephane Eranian's avatar Stephane Eranian Committed by Arnaldo Carvalho de Melo
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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: default avatarFrederic 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: default avatarStephane Eranian <eranian@google.com>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 8a0ecfb8

tools/perf/Documentation/perf-record.txt

+2 −2
Original line number Diff line number Diff line
@@ -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.

tools/perf/Documentation/perf-stat.txt

+2 −2
Original line number Diff line number Diff line
@@ -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

tools/perf/builtin-record.c

+6 −6
Original line number Diff line number Diff line
@@ -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,

tools/perf/builtin-stat.c

+5 −5
Original line number Diff line number Diff line
@@ -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,