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Subject[tip:perf/core] perf inject: Merge sched_stat_* and sched_switch events
Commit-ID:  26a031e136f4f8dc82c64df48cca0eb3b5d3eb4f
Gitweb: http://git.kernel.org/tip/26a031e136f4f8dc82c64df48cca0eb3b5d3eb4f
Author: Andrew Vagin <avagin@openvz.org>
AuthorDate: Tue, 7 Aug 2012 16:56:04 +0400
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Fri, 26 Oct 2012 11:22:25 -0200

perf inject: Merge sched_stat_* and sched_switch events

You may want to know where and how long a task is sleeping. A callchain
may be found in sched_switch and a time slice in stat_iowait, so I add
handler in perf inject for merging this events.

My code saves sched_switch event for each process and when it meets
stat_iowait, it reports the sched_switch event, because this event
contains a correct callchain. By another words it replaces all
stat_iowait events on proper sched_switch events.

I use the next sequence of commands for testing:

perf record -e sched:sched_stat_sleep -e sched:sched_switch \
-e sched:sched_process_exit -g -o ~/perf.data.raw \
~/test-program
perf inject -v -s -i ~/perf.data.raw -o ~/perf.data
perf report --stdio -i ~/perf.data
100.00% foo [kernel.kallsyms] [k] __schedule
|
--- __schedule
schedule
|
|--79.75%-- schedule_hrtimeout_range_clock
| schedule_hrtimeout_range
| poll_schedule_timeout
| do_select
| core_sys_select
| sys_select
| system_call_fastpath
| __select
| __libc_start_main
|
--20.25%-- do_nanosleep
hrtimer_nanosleep
sys_nanosleep
system_call_fastpath
__GI___libc_nanosleep
__libc_start_main

And here is test-program.c:

#include<unistd.h>
#include<time.h>
#include<sys/select.h>

int main()
{
struct timespec ts1;
struct timeval tv1;
int i;
long s;

for (i = 0; i < 10; i++) {
ts1.tv_sec = 0;
ts1.tv_nsec = 10000000;
nanosleep(&ts1, NULL);

tv1.tv_sec = 0;
tv1.tv_usec = 40000;
select(0, NULL, NULL, NULL,&tv1);
}
return 1;
}

Signed-off-by: Andrew Vagin <avagin@openvz.org>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1344344165-369636-4-git-send-email-avagin@openvz.org
[ committer note: Made it use evsel->handler ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/Documentation/perf-inject.txt | 5 +
tools/perf/builtin-inject.c | 142 +++++++++++++++++++++++++++++-
2 files changed, 144 insertions(+), 3 deletions(-)

diff --git a/tools/perf/Documentation/perf-inject.txt b/tools/perf/Documentation/perf-inject.txt
index 673ef97..a00a342 100644
--- a/tools/perf/Documentation/perf-inject.txt
+++ b/tools/perf/Documentation/perf-inject.txt
@@ -35,6 +35,11 @@ OPTIONS
-o::
--output=::
Output file name. (default: stdout)
+-s::
+--sched-stat::
+ Merge sched_stat and sched_switch for getting events where and how long
+ tasks slept. sched_switch contains a callchain where a task slept and
+ sched_stat contains a timeslice how long a task slept.

SEE ALSO
--------
diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index a706ed5..a4a3072 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -8,19 +8,32 @@
#include "builtin.h"

#include "perf.h"
+#include "util/color.h"
+#include "util/evlist.h"
+#include "util/evsel.h"
#include "util/session.h"
#include "util/tool.h"
#include "util/debug.h"

#include "util/parse-options.h"

+#include <linux/list.h>
+
struct perf_inject {
struct perf_tool tool;
bool build_ids;
+ bool sched_stat;
const char *input_name;
int pipe_output,
output;
u64 bytes_written;
+ struct list_head samples;
+};
+
+struct event_entry {
+ struct list_head node;
+ u32 tid;
+ union perf_event event[0];
};

static int perf_event__repipe_synth(struct perf_tool *tool,
@@ -86,12 +99,23 @@ static int perf_event__repipe(struct perf_tool *tool,
return perf_event__repipe_synth(tool, event, machine);
}

+typedef int (*inject_handler)(struct perf_tool *tool,
+ union perf_event *event,
+ struct perf_sample *sample,
+ struct perf_evsel *evsel,
+ struct machine *machine);
+
static int perf_event__repipe_sample(struct perf_tool *tool,
union perf_event *event,
- struct perf_sample *sample __maybe_unused,
- struct perf_evsel *evsel __maybe_unused,
- struct machine *machine)
+ struct perf_sample *sample,
+ struct perf_evsel *evsel,
+ struct machine *machine)
{
+ if (evsel->handler.func) {
+ inject_handler f = evsel->handler.func;
+ return f(tool, event, sample, evsel, machine);
+ }
+
return perf_event__repipe_synth(tool, event, machine);
}

@@ -216,6 +240,79 @@ repipe:
return 0;
}

+static int perf_inject__sched_process_exit(struct perf_tool *tool,
+ union perf_event *event __maybe_unused,
+ struct perf_sample *sample,
+ struct perf_evsel *evsel __maybe_unused,
+ struct machine *machine __maybe_unused)
+{
+ struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
+ struct event_entry *ent;
+
+ list_for_each_entry(ent, &inject->samples, node) {
+ if (sample->tid == ent->tid) {
+ list_del_init(&ent->node);
+ free(ent);
+ break;
+ }
+ }
+
+ return 0;
+}
+
+static int perf_inject__sched_switch(struct perf_tool *tool,
+ union perf_event *event,
+ struct perf_sample *sample,
+ struct perf_evsel *evsel,
+ struct machine *machine)
+{
+ struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
+ struct event_entry *ent;
+
+ perf_inject__sched_process_exit(tool, event, sample, evsel, machine);
+
+ ent = malloc(event->header.size + sizeof(struct event_entry));
+ if (ent == NULL) {
+ color_fprintf(stderr, PERF_COLOR_RED,
+ "Not enough memory to process sched switch event!");
+ return -1;
+ }
+
+ ent->tid = sample->tid;
+ memcpy(&ent->event, event, event->header.size);
+ list_add(&ent->node, &inject->samples);
+ return 0;
+}
+
+static int perf_inject__sched_stat(struct perf_tool *tool,
+ union perf_event *event __maybe_unused,
+ struct perf_sample *sample,
+ struct perf_evsel *evsel,
+ struct machine *machine)
+{
+ struct event_entry *ent;
+ union perf_event *event_sw;
+ struct perf_sample sample_sw;
+ struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
+ u32 pid = perf_evsel__intval(evsel, sample, "pid");
+
+ list_for_each_entry(ent, &inject->samples, node) {
+ if (pid == ent->tid)
+ goto found;
+ }
+
+ return 0;
+found:
+ event_sw = &ent->event[0];
+ perf_evsel__parse_sample(evsel, event_sw, &sample_sw);
+
+ sample_sw.period = sample->period;
+ sample_sw.time = sample->time;
+ perf_event__synthesize_sample(event_sw, evsel->attr.sample_type,
+ &sample_sw, false);
+ return perf_event__repipe(tool, event_sw, &sample_sw, machine);
+}
+
extern volatile int session_done;

static void sig_handler(int sig __maybe_unused)
@@ -223,6 +320,21 @@ static void sig_handler(int sig __maybe_unused)
session_done = 1;
}

+static int perf_evsel__check_stype(struct perf_evsel *evsel,
+ u64 sample_type, const char *sample_msg)
+{
+ struct perf_event_attr *attr = &evsel->attr;
+ const char *name = perf_evsel__name(evsel);
+
+ if (!(attr->sample_type & sample_type)) {
+ pr_err("Samples for %s event do not have %s attribute set.",
+ name, sample_msg);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
static int __cmd_inject(struct perf_inject *inject)
{
struct perf_session *session;
@@ -241,6 +353,26 @@ static int __cmd_inject(struct perf_inject *inject)
if (session == NULL)
return -ENOMEM;

+ if (inject->sched_stat) {
+ struct perf_evsel *evsel;
+
+ inject->tool.ordered_samples = true;
+
+ list_for_each_entry(evsel, &session->evlist->entries, node) {
+ const char *name = perf_evsel__name(evsel);
+
+ if (!strcmp(name, "sched:sched_switch")) {
+ if (perf_evsel__check_stype(evsel, PERF_SAMPLE_TID, "TID"))
+ return -EINVAL;
+
+ evsel->handler.func = perf_inject__sched_switch;
+ } else if (!strcmp(name, "sched:sched_process_exit"))
+ evsel->handler.func = perf_inject__sched_process_exit;
+ else if (!strncmp(name, "sched:sched_stat_", 17))
+ evsel->handler.func = perf_inject__sched_stat;
+ }
+ }
+
if (!inject->pipe_output)
lseek(inject->output, session->header.data_offset, SEEK_SET);

@@ -275,6 +407,7 @@ int cmd_inject(int argc, const char **argv, const char *prefix __maybe_unused)
.build_id = perf_event__repipe_op2_synth,
},
.input_name = "-",
+ .samples = LIST_HEAD_INIT(inject.samples),
};
const char *output_name = "-";
const struct option options[] = {
@@ -284,6 +417,9 @@ int cmd_inject(int argc, const char **argv, const char *prefix __maybe_unused)
"input file name"),
OPT_STRING('o', "output", &output_name, "file",
"output file name"),
+ OPT_BOOLEAN('s', "sched-stat", &inject.sched_stat,
+ "Merge sched-stat and sched-switch for getting events "
+ "where and how long tasks slept"),
OPT_INCR('v', "verbose", &verbose,
"be more verbose (show build ids, etc)"),
OPT_END()

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