Adding support for toggling events into record and stat
command. It's now possible to meassure/sample code
bounded by events.
The toggling events are defined via on/off terms,
assigned with the name of the event they should
toggle.
- Example: using k(ret)probes:
Define toggle(on/off) events:
# perf probe -a fork_entry=do_fork
# perf probe -a fork_exit=do_fork%return
Following record session samples only within do_fork function:
# perf record -g -e
'{cycles,cache-misses}:k,probe:fork_entry/on=cycles/,probe:fork_exit/off=cycles/'
\
perf bench sched messaging
Following stat session measure cycles within do_fork function:
# perf stat -e
'{cycles,cache-misses}:k,probe:fork_entry/on=cycles/,probe:fork_exit/off=cycles/'
\
perf bench sched messaging
# Running sched/messaging benchmark...
# 20 sender and receiver processes per group
# 1 groups == 40 processes run
Total time: 0.073 [sec]
Performance counter stats for './perf bench sched messaging -g 1':
20,935,464 cycles # 0.000 GHz
18,897 cache-misses
40 probe:fork_entry
40 probe:fork_exit
0.086319682 seconds time elapsed
- Example: using u(ret)probes:
Sample program:
---
void krava(void)
{
asm volatile ("nop; nop");
}
int main(void)
{
krava();
return 0;
}
---
Define toggle(on/off) events:
# perf probe -x ./ex entry=krava
# perf probe -x ./ex exit=krava%return
Following stat session measure instructions within krava function:
# perf stat -e
instructions:u,probe_ex:entry/on=instructions/,probe_ex:exit/off=instructions/
./ex
Performance counter stats for './ex':
9 instructions:u # 0.00 insns per cycle
1 probe_ex:entry
1 probe_ex:exit
0.000556743 seconds time elapsed
Following stat session measure cycles, instructions and cache-misses
within krava function:
# perf stat -e
'{cycles,instructions,cache-misses}:u,probe_ex:entry/on=cycles/,probe_ex:exit/off=cycles/'
./ex
Performance counter stats for './ex':
2,068 cycles # 0.000 GHz
9 instructions # 0.00 insns per cycle
0 cache-misses
1 probe_ex:entry
1 probe_ex:exit
0.000557504 seconds time elapsed
Signed-off-by: Jiri Olsa <jo...@redhat.com>
Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
Cc: Corey Ashford <cjash...@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweis...@gmail.com>
Cc: Ingo Molnar <mi...@elte.hu>
Cc: Paul Mackerras <pau...@samba.org>
Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
---
tools/perf/builtin-record.c | 7 ++++
tools/perf/builtin-stat.c | 12 +++++++
tools/perf/util/evlist.c | 87 +++++++++++++++++++++++++++++++++++++++++++++
tools/perf/util/evlist.h | 2 ++
tools/perf/util/evsel.c | 4 +++
tools/perf/util/evsel.h | 1 +
tools/perf/util/record.c | 2 ++
7 files changed, 115 insertions(+)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index da13840..a41d63c 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -225,6 +225,13 @@ try_again:
goto out;
}
+ if (perf_evlist__apply_toggle(evlist)) {
+ error("failed to set toggling %d (%s)\n", errno,
+ strerror(errno));
+ rc = -1;
+ goto out;
+ }
+
if (perf_evlist__mmap(evlist, opts->mmap_pages, false) < 0) {
if (errno == EPERM) {
pr_err("Permission error mapping pages.\n"
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index f686d5f..86729ae 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -242,6 +242,7 @@ static void perf_stat__reset_stats(struct perf_evlist
*evlist)
static int create_perf_stat_counter(struct perf_evsel *evsel)
{
struct perf_event_attr *attr = &evsel->attr;
+ struct perf_evsel *leader = evsel->leader;
if (scale)
attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
@@ -249,6 +250,9 @@ static int create_perf_stat_counter(struct perf_evsel
*evsel)
attr->inherit = !no_inherit;
+ if (leader->is_toggled)
+ attr->paused = 1;
+
if (perf_target__has_cpu(&target))
return perf_evsel__open_per_cpu(evsel, perf_evsel__cpus(evsel));
@@ -462,6 +466,8 @@ static int __run_perf_stat(int argc, const char **argv)
if (group)
perf_evlist__set_leader(evsel_list);
+ perf_evlist__mark_toggled(evsel_list);
+
list_for_each_entry(counter, &evsel_list->entries, node) {
if (create_perf_stat_counter(counter) < 0) {
/*
@@ -496,6 +502,12 @@ static int __run_perf_stat(int argc, const char **argv)
return -1;
}
+ if (perf_evlist__apply_toggle(evsel_list)) {
+ error("failed to set toggling with %d (%s)\n", errno,
+ strerror(errno));
+ return -1;
+ }
+
/*
* Enable counters and exec the command:
*/
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index c4d382d..eda7907 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -16,6 +16,7 @@
#include "evsel.h"
#include "debug.h"
#include <unistd.h>
+#include "asm/bug.h"
#include "parse-events.h"
#include "parse-options.h"
@@ -819,6 +820,91 @@ void perf_evlist__delete_maps(struct perf_evlist *evlist)
evlist->threads = NULL;
}
+static struct perf_evsel *
+perf_evlist__find_evsel_by_name(struct perf_evlist *evlist, char *name)
+{
+ struct perf_evsel *evsel;
+
+ list_for_each_entry(evsel, &evlist->entries, node)
+ if (strstr(perf_evsel__name(evsel), name))
+ return evsel;
+
+ return NULL;
+}
+
+static int apply_toggle(struct perf_evsel *evsel, struct perf_evsel *toggled,
+ int ncpus, int nthreads)
+{
+ int cpu, thread, err = 0;
+
+ for (cpu = 0; cpu < ncpus; cpu++) {
+ for (thread = 0; thread < nthreads; thread++) {
+ int fd = FD(evsel, cpu, thread);
+ u64 args[2] = {
+ FD(toggled, cpu, thread),
+ evsel->toggle_flag
+ };
+
+ err = ioctl(fd, PERF_EVENT_IOC_SET_TOGGLE, args);
+ if (err)
+ break;
+ }
+ }
+
+ return err;
+}
+
+int perf_evlist__apply_toggle(struct perf_evlist *evlist)
+{
+ struct perf_evsel *evsel;
+ int err = 0;
+ const int ncpus = cpu_map__nr(evlist->cpus),
+ nthreads = thread_map__nr(evlist->threads);
+
+ list_for_each_entry(evsel, &evlist->entries, node) {
+ struct perf_evsel *toggled;
+
+ if (!evsel->toggle_flag)
+ continue;
+
+ toggled = perf_evlist__find_evsel_by_name(evlist,
+ evsel->toggle_name);
+ if (WARN_ONCE(!toggled, "toggle apply: internal error\n"))
+ return -1;
+
+ pr_debug("toggle: %s toggles %s %s\n",
+ perf_evsel__name(evsel),
+ evsel->toggle_flag == PERF_FLAG_TOGGLE_ON ?
+ "ON" : "OFF",
+ perf_evsel__name(toggled));
+
+ err = apply_toggle(evsel, toggled, ncpus, nthreads);
+ if (err)
+ break;
+ }
+
+ return err;
+}
+
+void perf_evlist__mark_toggled(struct perf_evlist *evlist)
+{
+ struct perf_evsel *evsel;
+
+ list_for_each_entry(evsel, &evlist->entries, node) {
+ struct perf_evsel *toggled;
+
+ if (!evsel->toggle_flag)
+ continue;
+
+ toggled = perf_evlist__find_evsel_by_name(evlist,
+ evsel->toggle_name);
+ if (WARN_ONCE(!toggled, "toggle mark: internal error\n"))
+ continue;
+
+ toggled->is_toggled = true;
+ }
+}
+
int perf_evlist__apply_filters(struct perf_evlist *evlist)
{
struct perf_evsel *evsel;
@@ -827,6 +913,7 @@ int perf_evlist__apply_filters(struct perf_evlist *evlist)
nthreads = thread_map__nr(evlist->threads);
list_for_each_entry(evsel, &evlist->entries, node) {
+
if (evsel->filter == NULL)
continue;
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 0dbd8f8..eb77c81 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -135,6 +135,8 @@ static inline void perf_evlist__set_maps(struct perf_evlist
*evlist,
int perf_evlist__create_maps(struct perf_evlist *evlist,
struct perf_target *target);
void perf_evlist__delete_maps(struct perf_evlist *evlist);
+void perf_evlist__mark_toggled(struct perf_evlist *evlist);
+int perf_evlist__apply_toggle(struct perf_evlist *evlist);
int perf_evlist__apply_filters(struct perf_evlist *evlist);
void __perf_evlist__set_leader(struct list_head *list);
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 3ed7947..4e6db1c 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -696,6 +696,9 @@ void perf_evsel__config(struct perf_evsel *evsel,
*/
if (perf_target__none(&opts->target) &&
perf_evsel__is_group_leader(evsel))
attr->enable_on_exec = 1;
+
+ if (leader->is_toggled)
+ attr->paused = 1;
}
int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
@@ -984,6 +987,7 @@ static size_t perf_event_attr__fprintf(struct
perf_event_attr *attr, FILE *fp)
ret += PRINT_ATTR2(exclude_host, exclude_guest);
ret += PRINT_ATTR2N("excl.callchain_kern", exclude_callchain_kernel,
"excl.callchain_user", exclude_callchain_user);
+ ret += PRINT_ATTR2(paused, paused);
ret += PRINT_ATTR_U32(wakeup_events);
ret += PRINT_ATTR_U32(wakeup_watermark);
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index e70415b..69f4183 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -93,6 +93,7 @@ struct perf_evsel {
/* toggle event config */
char toggle_flag;
char *toggle_name;
+ bool is_toggled;
};
#define hists_to_evsel(h) container_of(h, struct perf_evsel, hists)
diff --git a/tools/perf/util/record.c b/tools/perf/util/record.c
index 18d73aa..7f7eeb4 100644
--- a/tools/perf/util/record.c
+++ b/tools/perf/util/record.c
@@ -88,6 +88,8 @@ void perf_evlist__config(struct perf_evlist *evlist,
if (evlist->cpus->map[0] < 0)
opts->no_inherit = true;
+ perf_evlist__mark_toggled(evlist);
+
list_for_each_entry(evsel, &evlist->entries, node)
perf_evsel__config(evsel, opts);
--
1.7.11.7
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