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Commit 930f8b34 authored by Jiri Olsa's avatar Jiri Olsa Committed by Arnaldo Carvalho de Melo
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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: default avatarJiri Olsa <jolsa@kernel.org>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180107160356.28203-13-jolsa@kernel.org


[ 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: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 2d1073de

tools/perf/Documentation/perf-report.txt

+4 −0
Original line number Diff line number Diff line
@@ -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

tools/perf/builtin-report.c

+134 −2
Original line number Diff line number Diff line
@@ -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 @@ int cmd_report(int argc, const char **argv) 
		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 @@ int cmd_report(int argc, const char **argv) 
			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);

	}