[PATCH 04/20] perf sched timehist: Add support for filtering on CPU
From: Arnaldo Carvalho de Melo
Date: Mon Jan 06 2020 - 11:07:42 EST
From: David Ahern <dsahern@xxxxxxxxx>
Allow user to limit output to one or more CPUs. Really helpful on
systems with a large number of cpus.
Committer testing:
# perf sched record -a sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 1.765 MB perf.data (1412 samples) ]
[root@quaco ~]# perf sched timehist | head
Samples do not have callchains.
time cpu task name wait time sch delay run time
[tid/pid] (msec) (msec) (msec)
--------------- ------ ------------------------------ --------- --------- ---------
66307.802686 [0000] perf[13086] 0.000 0.000 0.000
66307.802700 [0000] migration/0[12] 0.000 0.001 0.014
66307.802766 [0001] perf[13086] 0.000 0.000 0.000
66307.802774 [0001] migration/1[15] 0.000 0.001 0.007
66307.802841 [0002] perf[13086] 0.000 0.000 0.000
66307.802849 [0002] migration/2[20] 0.000 0.001 0.008
66307.802913 [0003] perf[13086] 0.000 0.000 0.000
#
# perf sched timehist --cpu 2 | head
Samples do not have callchains.
time cpu task name wait time sch delay run time
[tid/pid] (msec) (msec) (msec)
--------------- ------ ------------------------------ --------- --------- ---------
66307.802841 [0002] perf[13086] 0.000 0.000 0.000
66307.802849 [0002] migration/2[20] 0.000 0.001 0.008
66307.964485 [0002] <idle> 0.000 0.000 161.635
66307.964811 [0002] CPU 0/KVM[3589/3561] 0.000 0.056 0.325
66307.965477 [0002] <idle> 0.325 0.000 0.666
66307.965553 [0002] CPU 0/KVM[3589/3561] 0.666 0.024 0.076
66307.966456 [0002] <idle> 0.076 0.000 0.903
#
Signed-off-by: David Ahern <dsahern@xxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Link: http://lore.kernel.org/lkml/20191204173925.66976-1-dsahern@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/Documentation/perf-sched.txt | 4 ++++
tools/perf/builtin-sched.c | 13 +++++++++++++
2 files changed, 17 insertions(+)
diff --git a/tools/perf/Documentation/perf-sched.txt b/tools/perf/Documentation/perf-sched.txt
index 63f938b887dd..5fbe42bd599b 100644
--- a/tools/perf/Documentation/perf-sched.txt
+++ b/tools/perf/Documentation/perf-sched.txt
@@ -110,6 +110,10 @@ OPTIONS for 'perf sched timehist'
--max-stack::
Maximum number of functions to display in backtrace, default 5.
+-C=::
+--cpu=::
+ Only show events for the given CPU(s) (comma separated list).
+
-p=::
--pid=::
Only show events for given process ID (comma separated list).
diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 8a12d71364c3..82fcc2c15fe4 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -51,6 +51,9 @@
#define SYM_LEN 129
#define MAX_PID 1024000
+static const char *cpu_list;
+static DECLARE_BITMAP(cpu_bitmap, MAX_NR_CPUS);
+
struct sched_atom;
struct task_desc {
@@ -2008,6 +2011,9 @@ static void timehist_print_sample(struct perf_sched *sched,
char nstr[30];
u64 wait_time;
+ if (cpu_list && !test_bit(sample->cpu, cpu_bitmap))
+ return;
+
timestamp__scnprintf_usec(t, tstr, sizeof(tstr));
printf("%15s [%04d] ", tstr, sample->cpu);
@@ -2994,6 +3000,12 @@ static int perf_sched__timehist(struct perf_sched *sched)
if (IS_ERR(session))
return PTR_ERR(session);
+ if (cpu_list) {
+ err = perf_session__cpu_bitmap(session, cpu_list, cpu_bitmap);
+ if (err < 0)
+ goto out;
+ }
+
evlist = session->evlist;
symbol__init(&session->header.env);
@@ -3429,6 +3441,7 @@ int cmd_sched(int argc, const char **argv)
"analyze events only for given process id(s)"),
OPT_STRING('t', "tid", &symbol_conf.tid_list_str, "tid[,tid...]",
"analyze events only for given thread id(s)"),
+ OPT_STRING('C', "cpu", &cpu_list, "cpu", "list of cpus to profile"),
OPT_PARENT(sched_options)
};
--
2.21.1