[tip:perf/core] perf sched timehist: Add call graph options

From: tip-bot for David Ahern
Date: Wed Nov 23 2016 - 23:21:13 EST

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Commit-ID: 6c973c90852c3fa4b4e76a061ce89dcd373efccc
Gitweb: http://git.kernel.org/tip/6c973c90852c3fa4b4e76a061ce89dcd373efccc
Author: David Ahern <dsahern@xxxxxxxxx>
AuthorDate: Wed, 16 Nov 2016 15:06:32 +0900
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Wed, 23 Nov 2016 10:44:09 -0300

perf sched timehist: Add call graph options

If callchains were recorded they are appended to the line with a default stack depth of 5:

1.874569 [0011] gcc[31949] 0.014 0.000 1.148 wait_for_completion_killable <- do_fork <- sys_vfork <- stub_vfork <- __vfork
1.874591 [0010] gcc[31951] 0.000 0.000 0.024 __cond_resched <- _cond_resched <- wait_for_completion <- stop_one_cpu <- sched_exec
1.874603 [0010] migration/10[59] 3.350 0.004 0.011 smpboot_thread_fn <- kthread <- ret_from_fork
1.874604 [0011] <idle> 1.148 0.000 0.035 cpu_startup_entry <- start_secondary
1.874723 [0005] <idle> 0.016 0.000 1.383 cpu_startup_entry <- start_secondary
1.874746 [0005] gcc[31949] 0.153 0.078 0.022 do_wait sys_wait4 <- system_call_fastpath <- __GI___waitpid

--no-call-graph can be used to not show the callchains. --max-stack is used
to control the number of frames shown (default of 5). -x/--excl options can
be used to collapse redundant callchains to get more relevant data on screen.

Signed-off-by: David Ahern <dsahern@xxxxxxxxx>
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/20161116060634.28477-7-namhyung@xxxxxxxxxx
[ Add documentation based on above commit message ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/Documentation/perf-sched.txt | 7 +++
tools/perf/builtin-sched.c | 88 ++++++++++++++++++++++++++++++---
2 files changed, 89 insertions(+), 6 deletions(-)

diff --git a/tools/perf/Documentation/perf-sched.txt b/tools/perf/Documentation/perf-sched.txt
index 9a77bc7..8345208 100644
--- a/tools/perf/Documentation/perf-sched.txt
+++ b/tools/perf/Documentation/perf-sched.txt
@@ -99,6 +99,13 @@ OPTIONS for 'perf sched timehist'
--kallsyms=<file>::
kallsyms pathname

+-g::
+--no-call-graph::
+ Do not display call chains if present.
+
+--max-stack::
+ Maximum number of functions to display in backtrace, default 5.
+
-s::
--summary::
Show only a summary of scheduling by thread with min, max, and average
diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 8fb7bcc..1f87316 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -14,6 +14,7 @@
#include "util/thread_map.h"
#include "util/color.h"
#include "util/stat.h"
+#include "util/callchain.h"

#include <subcmd/parse-options.h>
#include "util/trace-event.h"
@@ -198,6 +199,8 @@ struct perf_sched {
/* options for timehist command */
bool summary;
bool summary_only;
+ bool show_callchain;
+ unsigned int max_stack;
bool show_wakeups;
u64 skipped_samples;
};
@@ -1810,6 +1813,7 @@ static void timehist_header(void)

static void timehist_print_sample(struct perf_sched *sched,
struct perf_sample *sample,
+ struct addr_location *al,
struct thread *thread)
{
struct thread_runtime *tr = thread__priv(thread);
@@ -1827,6 +1831,18 @@ static void timehist_print_sample(struct perf_sched *sched,
if (sched->show_wakeups)
printf(" %-*s", comm_width, "");

+ if (thread->tid == 0)
+ goto out;
+
+ if (sched->show_callchain)
+ printf(" ");
+
+ sample__fprintf_sym(sample, al, 0,
+ EVSEL__PRINT_SYM | EVSEL__PRINT_ONELINE |
+ EVSEL__PRINT_CALLCHAIN_ARROW,
+ &callchain_cursor, stdout);
+
+out:
printf("\n");
}

@@ -1878,9 +1894,14 @@ static void timehist_update_runtime_stats(struct thread_runtime *r,
r->total_run_time += r->dt_run;
}

-static bool is_idle_sample(struct perf_sample *sample,
- struct perf_evsel *evsel)
+static bool is_idle_sample(struct perf_sched *sched,
+ struct perf_sample *sample,
+ struct perf_evsel *evsel,
+ struct machine *machine)
{
+ struct thread *thread;
+ struct callchain_cursor *cursor = &callchain_cursor;
+
/* pid 0 == swapper == idle task */
if (sample->pid == 0)
return true;
@@ -1889,6 +1910,25 @@ static bool is_idle_sample(struct perf_sample *sample,
if (perf_evsel__intval(evsel, sample, "prev_pid") == 0)
return true;
}
+
+ /* want main thread for process - has maps */
+ thread = machine__findnew_thread(machine, sample->pid, sample->pid);
+ if (thread == NULL) {
+ pr_debug("Failed to get thread for pid %d.\n", sample->pid);
+ return false;
+ }
+
+ if (!symbol_conf.use_callchain || sample->callchain == NULL)
+ return false;
+
+ if (thread__resolve_callchain(thread, cursor, evsel, sample,
+ NULL, NULL, sched->max_stack) != 0) {
+ if (verbose)
+ error("Failed to resolve callchain. Skipping\n");
+
+ return false;
+ }
+ callchain_cursor_commit(cursor);
return false;
}

@@ -1999,13 +2039,14 @@ static struct thread_runtime *thread__get_runtime(struct thread *thread)
return tr;
}

-static struct thread *timehist_get_thread(struct perf_sample *sample,
+static struct thread *timehist_get_thread(struct perf_sched *sched,
+ struct perf_sample *sample,
struct machine *machine,
struct perf_evsel *evsel)
{
struct thread *thread;

- if (is_idle_sample(sample, evsel)) {
+ if (is_idle_sample(sched, sample, evsel, machine)) {
thread = get_idle_thread(sample->cpu);
if (thread == NULL)
pr_err("Failed to get idle thread for cpu %d.\n", sample->cpu);
@@ -2115,7 +2156,7 @@ static int timehist_sched_change_event(struct perf_tool *tool,
goto out;
}

- thread = timehist_get_thread(sample, machine, evsel);
+ thread = timehist_get_thread(sched, sample, machine, evsel);
if (thread == NULL) {
rc = -1;
goto out;
@@ -2134,7 +2175,7 @@ static int timehist_sched_change_event(struct perf_tool *tool,

timehist_update_runtime_stats(tr, sample->time, tprev);
if (!sched->summary_only)
- timehist_print_sample(sched, sample, thread);
+ timehist_print_sample(sched, sample, &al, thread);

out:
if (tr) {
@@ -2327,6 +2368,30 @@ static int perf_timehist__process_sample(struct perf_tool *tool,
return err;
}

+static int timehist_check_attr(struct perf_sched *sched,
+ struct perf_evlist *evlist)
+{
+ struct perf_evsel *evsel;
+ struct evsel_runtime *er;
+
+ list_for_each_entry(evsel, &evlist->entries, node) {
+ er = perf_evsel__get_runtime(evsel);
+ if (er == NULL) {
+ pr_err("Failed to allocate memory for evsel runtime data\n");
+ return -1;
+ }
+
+ if (sched->show_callchain &&
+ !(evsel->attr.sample_type & PERF_SAMPLE_CALLCHAIN)) {
+ pr_info("Samples do not have callchains.\n");
+ sched->show_callchain = 0;
+ symbol_conf.use_callchain = 0;
+ }
+ }
+
+ return 0;
+}
+
static int perf_sched__timehist(struct perf_sched *sched)
{
const struct perf_evsel_str_handler handlers[] = {
@@ -2359,6 +2424,8 @@ static int perf_sched__timehist(struct perf_sched *sched)
sched->tool.ordered_events = true;
sched->tool.ordering_requires_timestamps = true;

+ symbol_conf.use_callchain = sched->show_callchain;
+
session = perf_session__new(&file, false, &sched->tool);
if (session == NULL)
return -ENOMEM;
@@ -2367,6 +2434,9 @@ static int perf_sched__timehist(struct perf_sched *sched)

symbol__init(&session->header.env);

+ if (timehist_check_attr(sched, evlist) != 0)
+ goto out;
+
setup_pager();

/* setup per-evsel handlers */
@@ -2714,6 +2784,8 @@ int cmd_sched(int argc, const char **argv, const char *prefix __maybe_unused)
.next_shortname1 = 'A',
.next_shortname2 = '0',
.skip_merge = 0,
+ .show_callchain = 1,
+ .max_stack = 5,
};
const struct option sched_options[] = {
OPT_STRING('i', "input", &input_name, "file",
@@ -2759,6 +2831,10 @@ int cmd_sched(int argc, const char **argv, const char *prefix __maybe_unused)
"file", "vmlinux pathname"),
OPT_STRING(0, "kallsyms", &symbol_conf.kallsyms_name,
"file", "kallsyms pathname"),
+ OPT_BOOLEAN('g', "call-graph", &sched.show_callchain,
+ "Display call chains if present (default on)"),
+ OPT_UINTEGER(0, "max-stack", &sched.max_stack,
+ "Maximum number of functions to display backtrace."),
OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
"Look for files with symbols relative to this directory"),
OPT_BOOLEAN('s', "summary", &sched.summary_only,

Next message: Ingo Molnar: "Re: [PATCH 00/14] export perf overheads information"
Previous message: David Singleton: "[PATCH] pcie: aer: aerdrv: PCIe AER workaround and handling for ASR1K platforms."
In reply to: Namhyung Kim: "[PATCH v2 6/8] perf sched timehist: Add call graph options"
Next in thread: Namhyung Kim: "[PATCH v2 8/8] perf sched: Add documentation for timehist options"
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