perf record: Add missing -C option support for specifying profile cpu
perf top supports a -C for setting the profile CPU, but perf
record does not. This adds the same option for perf record,
allowing the user to specify a specific target profile CPU.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20090812091801.GC12579@kernel.dk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 30b83de..de76008 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -35,6 +35,7 @@
static int group = 0;
static unsigned int realtime_prio = 0;
static int system_wide = 0;
+static int profile_cpu = -1;
static pid_t target_pid = -1;
static int inherit = 1;
static int force = 0;
@@ -431,6 +432,8 @@
if (err == EPERM)
die("Permission error - are you root?\n");
+ else if (err == ENODEV && profile_cpu != -1)
+ die("No such device - did you specify an out-of-range profile CPU?\n");
/*
* If it's cycles then fall back to hrtimer
@@ -564,9 +567,15 @@
if (pid == -1)
pid = getpid();
- open_counters(-1, pid);
- } else for (i = 0; i < nr_cpus; i++)
- open_counters(i, target_pid);
+ open_counters(profile_cpu, pid);
+ } else {
+ if (profile_cpu != -1) {
+ open_counters(profile_cpu, target_pid);
+ } else {
+ for (i = 0; i < nr_cpus; i++)
+ open_counters(i, target_pid);
+ }
+ }
if (file_new)
perf_header__write(header, output);
@@ -645,6 +654,8 @@
"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_BOOLEAN('f', "force", &force,
"overwrite existing data file"),
OPT_LONG('c', "count", &default_interval,