perf tools: Add the ability to specify list of cpus to monitor
This patch adds a -C option to stat, record, top to designate a list of CPUs to
monitor. CPUs can be specified as a comma-separated list or ranges, no space
allowed.
Examples:
$ perf record -a -C0-1,4-7 sleep 1
$ perf top -C0-4
$ perf stat -a -C1,2,3,4 sleep 1
With perf record in per-thread mode with inherit mode on, samples are collected
only when the thread runs on the designated CPUs.
The -C option does not turn on system-wide mode automatically.
Cc: David S. Miller <davem@davemloft.net>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <4bff9496.d345d80a.41fe.7b00@mx.google.com>
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index dc3435e..f28c4bb 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -49,7 +49,6 @@
static int realtime_prio = 0;
static bool raw_samples = false;
static bool system_wide = false;
-static int profile_cpu = -1;
static pid_t target_pid = -1;
static pid_t target_tid = -1;
static pid_t *all_tids = NULL;
@@ -74,6 +73,7 @@
static off_t post_processing_offset;
static struct perf_session *session;
+static const char *cpu_list;
struct mmap_data {
int counter;
@@ -300,7 +300,7 @@
die("Permission error - are you root?\n"
"\t Consider tweaking"
" /proc/sys/kernel/perf_event_paranoid.\n");
- else if (err == ENODEV && profile_cpu != -1) {
+ else if (err == ENODEV && cpu_list) {
die("No such device - did you specify"
" an out-of-range profile CPU?\n");
}
@@ -622,10 +622,15 @@
close(child_ready_pipe[0]);
}
- if ((!system_wide && no_inherit) || profile_cpu != -1) {
- open_counters(profile_cpu);
+ nr_cpus = read_cpu_map(cpu_list);
+ if (nr_cpus < 1) {
+ perror("failed to collect number of CPUs\n");
+ return -1;
+ }
+
+ if (!system_wide && no_inherit && !cpu_list) {
+ open_counters(-1);
} else {
- nr_cpus = read_cpu_map();
for (i = 0; i < nr_cpus; i++)
open_counters(cpumap[i]);
}
@@ -704,7 +709,7 @@
if (perf_guest)
perf_session__process_machines(session, event__synthesize_guest_os);
- if (!system_wide && profile_cpu == -1)
+ if (!system_wide && cpu_list)
event__synthesize_thread(target_tid, process_synthesized_event,
session);
else
@@ -794,8 +799,8 @@
"system-wide collection from all CPUs"),
OPT_BOOLEAN('A', "append", &append_file,
"append to the output file to do incremental profiling"),
- OPT_INTEGER('C', "profile_cpu", &profile_cpu,
- "CPU to profile on"),
+ OPT_STRING('C', "cpu", &cpu_list, "cpu",
+ "list of cpus to monitor"),
OPT_BOOLEAN('f', "force", &force,
"overwrite existing data file (deprecated)"),
OPT_U64('c', "count", &user_interval, "event period to sample"),
@@ -825,7 +830,7 @@
argc = parse_options(argc, argv, options, record_usage,
PARSE_OPT_STOP_AT_NON_OPTION);
if (!argc && target_pid == -1 && target_tid == -1 &&
- !system_wide && profile_cpu == -1)
+ !system_wide && !cpu_list)
usage_with_options(record_usage, options);
if (force && append_file) {