[tip:perf/core] perf report: Add --tasks option to display monitored tasks
From: tip-bot for Jiri Olsa
Date: Thu Jan 11 2018 - 01:32:52 EST
Commit-ID: 930f8b3479444d264aa33e008c4b00b86e8c62cc
Gitweb: https://git.kernel.org/tip/930f8b3479444d264aa33e008c4b00b86e8c62cc
Author: Jiri Olsa <jolsa@xxxxxxxxxx>
AuthorDate: Sun, 7 Jan 2018 17:03:56 +0100
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Wed, 10 Jan 2018 12:00:56 -0300
perf report: Add --tasks option to display monitored tasks
Add --tasks option to display monitored tasks stored in perf.data.
Displaying pid/tid/ppid plus the command string aligned to distinguish
parent and child tasks.
$ perf record -a
...
$ perf report --tasks
# pid tid ppid comm
0 0 -1 |swapper
2 2 0 | kthreadd
14080 14080 2 | kworker/u17:1
4 4 2 | kworker/0:0H
6 6 2 | mm_percpu_wq
...
1 1 0 | systemd
23242 23242 1 | firefox
23242 23298 23242 | Cache2 I/O
23242 23304 23242 | GMPThread
...
1195 1195 1 | login
1611 1611 1195 | bash
1639 1639 1611 | startx
1663 1663 1639 | xinit
1673 1673 1663 | xmonad-x86_64-l
23939 23939 1673 | xterm
23941 23941 23939 | bash
23963 23963 23941 | mutt
24954 24954 23963 | offlineimap
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20180107160356.28203-13-jolsa@xxxxxxxxxx
[ Make it --tasks, plural, --task works as well, as its unambiguous ]
[ Use machine__find_thread(), not findnew(), as pointed out by Namhyung ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/Documentation/perf-report.txt | 4 +
tools/perf/builtin-report.c | 136 ++++++++++++++++++++++++++++++-
2 files changed, 138 insertions(+), 2 deletions(-)
diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index a7d11ef..856c3c7 100644
--- a/tools/perf/Documentation/perf-report.txt
+++ b/tools/perf/Documentation/perf-report.txt
@@ -461,6 +461,10 @@ include::itrace.txt[]
Display overall events statistics without any further processing.
(like the one at the end of the perf report -D command)
+--tasks::
+ Display monitored tasks stored in perf data. Displaying pid/tid/ppid
+ plus the command string aligned to distinguish parent and child tasks.
+
include::callchain-overhead-calculation.txt[]
SEE ALSO
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 8e67a8c..2c7bd85 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -15,6 +15,7 @@
#include "util/color.h"
#include <linux/list.h>
#include <linux/rbtree.h>
+#include <linux/err.h>
#include "util/symbol.h"
#include "util/callchain.h"
#include "util/values.h"
@@ -63,6 +64,7 @@ struct report {
bool inverted_callchain;
bool mem_mode;
bool stats_mode;
+ bool tasks_mode;
bool header;
bool header_only;
bool nonany_branch_mode;
@@ -603,6 +605,124 @@ static int stats_print(struct report *rep)
return 0;
}
+static void tasks_setup(struct report *rep)
+{
+ memset(&rep->tool, 0, sizeof(rep->tool));
+ rep->tool.comm = perf_event__process_comm;
+ rep->tool.exit = perf_event__process_exit;
+ rep->tool.fork = perf_event__process_fork;
+ rep->tool.no_warn = true;
+}
+
+struct task {
+ struct thread *thread;
+ struct list_head list;
+ struct list_head children;
+};
+
+static struct task *tasks_list(struct task *task, struct machine *machine)
+{
+ struct thread *parent_thread, *thread = task->thread;
+ struct task *parent_task;
+
+ /* Already listed. */
+ if (!list_empty(&task->list))
+ return NULL;
+
+ /* Last one in the chain. */
+ if (thread->ppid == -1)
+ return task;
+
+ parent_thread = machine__find_thread(machine, -1, thread->ppid);
+ if (!parent_thread)
+ return ERR_PTR(-ENOENT);
+
+ parent_task = thread__priv(parent_thread);
+ list_add_tail(&task->list, &parent_task->children);
+ return tasks_list(parent_task, machine);
+}
+
+static void task__print_level(struct task *task, FILE *fp, int level)
+{
+ struct thread *thread = task->thread;
+ struct task *child;
+
+ fprintf(fp, " %8d %8d %8d |%*s%s\n",
+ thread->pid_, thread->tid, thread->ppid,
+ level, "", thread__comm_str(thread));
+
+ if (!list_empty(&task->children)) {
+ list_for_each_entry(child, &task->children, list)
+ task__print_level(child, fp, level + 1);
+ }
+}
+
+static int tasks_print(struct report *rep, FILE *fp)
+{
+ struct perf_session *session = rep->session;
+ struct machine *machine = &session->machines.host;
+ struct task *tasks, *task;
+ unsigned int nr = 0, itask = 0, i;
+ struct rb_node *nd;
+ LIST_HEAD(list);
+
+ /*
+ * No locking needed while accessing machine->threads,
+ * because --tasks is single threaded command.
+ */
+
+ /* Count all the threads. */
+ for (i = 0; i < THREADS__TABLE_SIZE; i++)
+ nr += machine->threads[i].nr;
+
+ tasks = malloc(sizeof(*tasks) * nr);
+ if (!tasks)
+ return -ENOMEM;
+
+ for (i = 0; i < THREADS__TABLE_SIZE; i++) {
+ struct threads *threads = &machine->threads[i];
+
+ for (nd = rb_first(&threads->entries); nd; nd = rb_next(nd)) {
+ task = tasks + itask++;
+
+ task->thread = rb_entry(nd, struct thread, rb_node);
+ INIT_LIST_HEAD(&task->children);
+ INIT_LIST_HEAD(&task->list);
+ thread__set_priv(task->thread, task);
+ }
+ }
+
+ /*
+ * Iterate every task down to the unprocessed parent
+ * and link all in task children list. Task with no
+ * parent is added into 'list'.
+ */
+ for (itask = 0; itask < nr; itask++) {
+ task = tasks + itask;
+
+ if (!list_empty(&task->list))
+ continue;
+
+ task = tasks_list(task, machine);
+ if (IS_ERR(task)) {
+ pr_err("Error: failed to process tasks\n");
+ free(tasks);
+ return PTR_ERR(task);
+ }
+
+ if (task)
+ list_add_tail(&task->list, &list);
+ }
+
+ fprintf(fp, "# %8s %8s %8s %s\n", "pid", "tid", "ppid", "comm");
+
+ list_for_each_entry(task, &list, list)
+ task__print_level(task, fp, 0);
+
+ free(tasks);
+ return 0;
+}
+
static int __cmd_report(struct report *rep)
{
int ret;
@@ -637,6 +757,9 @@ static int __cmd_report(struct report *rep)
if (rep->stats_mode)
stats_setup(rep);
+ if (rep->tasks_mode)
+ tasks_setup(rep);
+
ret = perf_session__process_events(session);
if (ret) {
ui__error("failed to process sample\n");
@@ -646,6 +769,9 @@ static int __cmd_report(struct report *rep)
if (rep->stats_mode)
return stats_print(rep);
+ if (rep->tasks_mode)
+ return tasks_print(rep, stdout);
+
report__warn_kptr_restrict(rep);
evlist__for_each_entry(session->evlist, pos)
@@ -803,6 +929,7 @@ int cmd_report(int argc, const char **argv)
OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
"dump raw trace in ASCII"),
OPT_BOOLEAN(0, "stats", &report.stats_mode, "Display event stats"),
+ OPT_BOOLEAN(0, "tasks", &report.tasks_mode, "Display recorded tasks"),
OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
"file", "vmlinux pathname"),
OPT_STRING(0, "kallsyms", &symbol_conf.kallsyms_name,
@@ -1064,8 +1191,12 @@ repeat:
report.tool.show_feat_hdr = SHOW_FEAT_HEADER;
if (report.show_full_info)
report.tool.show_feat_hdr = SHOW_FEAT_HEADER_FULL_INFO;
- if (report.stats_mode)
+ if (report.stats_mode || report.tasks_mode)
use_browser = 0;
+ if (report.stats_mode && report.tasks_mode) {
+ pr_err("Error: --tasks and --stats options cannot be used together\n");
+ goto error;
+ }
if (strcmp(input_name, "-") != 0)
setup_browser(true);
@@ -1088,7 +1219,8 @@ repeat:
ret = 0;
goto error;
}
- } else if (use_browser == 0 && !quiet && !report.stats_mode) {
+ } else if (use_browser == 0 && !quiet &&
+ !report.stats_mode && !report.tasks_mode) {
fputs("# To display the perf.data header info, please use --header/--header-only options.\n#\n",
stdout);
}