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Message-Id: <1347976585-3816541-1-git-send-email-avagin@openvz.org>
Date: Tue, 18 Sep 2012 17:56:25 +0400
From: Andrew Vagin <avagin@...nvz.org>
To: linux-kernel@...r.kernel.org
Cc: Andrew Vagin <avagin@...nvz.org>,
Arnaldo Carvalho de Melo <acme@...stprotocols.net>,
Frederic Weisbecker <fweisbec@...il.com>,
Peter Zijlstra <a.p.zijlstra@...llo.nl>,
Paul Mackerras <paulus@...ba.org>,
Ingo Molnar <mingo@...hat.com>,
Andi Kleen <andi@...stfloor.org>,
David Ahern <dsahern@...il.com>
Subject: [PATCH] perf: teach perf inject to merge sched_stat_* and sched_switch events (v3)
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.
v2: - remove the global variable "session"
- hadle errors from malloc()
v3: - use sample->tid instead of sample->pid for merging events.
Frederic Weisbecker noticed that this code works only in a root pidns.
It's true, because a pid from trace content is not pid-namespace safe
and currently no way to get this pid in a current pidns. This problem
is more general, so I don't think that it should be solved in this series.
Cc: Arnaldo Carvalho de Melo <acme@...stprotocols.net>
Cc: Frederic Weisbecker <fweisbec@...il.com>
Cc: Peter Zijlstra <a.p.zijlstra@...llo.nl>
Cc: Paul Mackerras <paulus@...ba.org>,
Cc: Ingo Molnar <mingo@...hat.com
Cc: Andi Kleen <andi@...stfloor.org>
Cc: David Ahern <dsahern@...il.com>
Signed-off-by: Andrew Vagin <avagin@...nvz.org>
---
tools/perf/Documentation/perf-inject.txt | 4 ++
tools/perf/builtin-inject.c | 86 ++++++++++++++++++++++++++++++
2 files changed, 90 insertions(+), 0 deletions(-)
diff --git a/tools/perf/Documentation/perf-inject.txt b/tools/perf/Documentation/perf-inject.txt
index 6be2101..c04e0c6 100644
--- a/tools/perf/Documentation/perf-inject.txt
+++ b/tools/perf/Documentation/perf-inject.txt
@@ -35,6 +35,10 @@ 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.
SEE ALSO
--------
diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index ed12b19..1783f0a 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -8,11 +8,13 @@
#include "builtin.h"
#include "perf.h"
+#include "util/evsel.h"
#include "util/session.h"
#include "util/tool.h"
#include "util/debug.h"
#include "util/parse-options.h"
+#include "util/trace-event.h"
static const char *input_name = "-";
static const char *output_name = "-";
@@ -21,6 +23,7 @@ static int output;
static u64 bytes_written;
static bool inject_build_ids;
+static bool inject_sched_stat;
static int perf_event__repipe_synth(struct perf_tool *tool __used,
union perf_event *event,
@@ -213,6 +216,83 @@ repipe:
return 0;
}
+struct event_entry {
+ struct list_head node;
+ u32 tid;
+ union perf_event event[0];
+};
+
+static LIST_HEAD(samples);
+
+static int perf_event__sched_stat(struct perf_tool *tool,
+ union perf_event *event,
+ struct perf_sample *sample,
+ struct perf_evsel *evsel,
+ struct machine *machine)
+{
+ const char *evname = NULL;
+ uint32_t size;
+ struct event_entry *ent;
+ union perf_event *event_sw = NULL;
+ struct perf_sample sample_sw;
+ int sched_process_exit;
+
+ size = event->header.size;
+
+ evname = evsel->tp_format->name;
+
+ sched_process_exit = !strcmp(evname, "sched_process_exit");
+
+ if (!strcmp(evname, "sched_switch") || sched_process_exit) {
+ list_for_each_entry(ent, &samples, node)
+ if (sample->tid == ent->tid)
+ break;
+
+ if (&ent->node != &samples) {
+ list_del(&ent->node);
+ free(ent);
+ }
+
+ if (sched_process_exit)
+ return 0;
+
+ ent = malloc(size + sizeof(struct event_entry));
+ if (ent == NULL)
+ die("malloc");
+ ent->tid = sample->tid;
+ memcpy(&ent->event, event, size);
+ list_add(&ent->node, &samples);
+ return 0;
+
+ } else if (!strncmp(evname, "sched_stat_", 11)) {
+ u32 pid;
+
+ pid = raw_field_value(evsel->tp_format,
+ "pid", sample->raw_data);
+
+ list_for_each_entry(ent, &samples, node) {
+ if (pid == ent->tid)
+ break;
+ }
+
+ if (&ent->node == &samples)
+ return 0;
+
+ event_sw = &ent->event[0];
+ perf_evsel__parse_sample(evsel, event_sw, &sample_sw, false);
+
+ sample_sw.period = sample->period;
+ sample_sw.time = sample->time;
+ perf_evsel__synthesize_sample(evsel, event_sw, &sample_sw, false);
+
+ perf_event__repipe(tool, event_sw, &sample_sw, machine);
+ return 0;
+ }
+
+ perf_event__repipe(tool, event, sample, machine);
+
+ return 0;
+}
struct perf_tool perf_inject = {
.sample = perf_event__repipe_sample,
.mmap = perf_event__repipe,
@@ -248,6 +328,9 @@ static int __cmd_inject(void)
perf_inject.mmap = perf_event__repipe_mmap;
perf_inject.fork = perf_event__repipe_task;
perf_inject.tracing_data = perf_event__repipe_tracing_data;
+ } else if (inject_sched_stat) {
+ perf_inject.sample = perf_event__sched_stat;
+ perf_inject.ordered_samples = true;
}
session = perf_session__new(input_name, O_RDONLY, false, true, &perf_inject);
@@ -275,6 +358,9 @@ static const char * const report_usage[] = {
static const struct option options[] = {
OPT_BOOLEAN('b', "build-ids", &inject_build_ids,
"Inject build-ids into the output stream"),
+ OPT_BOOLEAN('s', "sched-stat", &inject_sched_stat,
+ "Merge sched-stat and sched-switch for getting events "
+ "where and how long tasks slept"),
OPT_STRING('i', "input", &input_name, "file",
"input file name"),
OPT_STRING('o', "output", &output_name, "file",
--
1.7.1
--
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