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-stat.c b/tools/perf/builtin-stat.c
index 9a39ca3..a6b4d44 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -69,7 +69,7 @@
};
static bool system_wide = false;
-static unsigned int nr_cpus = 0;
+static int nr_cpus = 0;
static int run_idx = 0;
static int run_count = 1;
@@ -82,6 +82,7 @@
static pid_t child_pid = -1;
static bool null_run = false;
static bool big_num = false;
+static const char *cpu_list;
static int *fd[MAX_NR_CPUS][MAX_COUNTERS];
@@ -158,7 +159,7 @@
PERF_FORMAT_TOTAL_TIME_RUNNING;
if (system_wide) {
- unsigned int cpu;
+ int cpu;
for (cpu = 0; cpu < nr_cpus; cpu++) {
fd[cpu][counter][0] = sys_perf_event_open(attr,
@@ -208,7 +209,7 @@
static void read_counter(int counter)
{
u64 count[3], single_count[3];
- unsigned int cpu;
+ int cpu;
size_t res, nv;
int scaled;
int i, thread;
@@ -542,6 +543,8 @@
"null run - dont start any counters"),
OPT_BOOLEAN('B', "big-num", &big_num,
"print large numbers with thousands\' separators"),
+ OPT_STRING('C', "cpu", &cpu_list, "cpu",
+ "list of cpus to monitor in system-wide"),
OPT_END()
};
@@ -566,10 +569,13 @@
}
if (system_wide)
- nr_cpus = read_cpu_map();
+ nr_cpus = read_cpu_map(cpu_list);
else
nr_cpus = 1;
+ if (nr_cpus < 1)
+ usage_with_options(stat_usage, options);
+
if (target_pid != -1) {
target_tid = target_pid;
thread_num = find_all_tid(target_pid, &all_tids);