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/util/cpumap.c b/tools/perf/util/cpumap.c
index 4e01490..0f9b8d7 100644
--- a/tools/perf/util/cpumap.c
+++ b/tools/perf/util/cpumap.c
@@ -20,7 +20,7 @@
return nr_cpus;
}
-int read_cpu_map(void)
+static int read_all_cpu_map(void)
{
FILE *onlnf;
int nr_cpus = 0;
@@ -57,3 +57,58 @@
return default_cpu_map();
}
+
+int read_cpu_map(const char *cpu_list)
+{
+ unsigned long start_cpu, end_cpu = 0;
+ char *p = NULL;
+ int i, nr_cpus = 0;
+
+ if (!cpu_list)
+ return read_all_cpu_map();
+
+ if (!isdigit(*cpu_list))
+ goto invalid;
+
+ while (isdigit(*cpu_list)) {
+ p = NULL;
+ start_cpu = strtoul(cpu_list, &p, 0);
+ if (start_cpu >= INT_MAX
+ || (*p != '\0' && *p != ',' && *p != '-'))
+ goto invalid;
+
+ if (*p == '-') {
+ cpu_list = ++p;
+ p = NULL;
+ end_cpu = strtoul(cpu_list, &p, 0);
+
+ if (end_cpu >= INT_MAX || (*p != '\0' && *p != ','))
+ goto invalid;
+
+ if (end_cpu < start_cpu)
+ goto invalid;
+ } else {
+ end_cpu = start_cpu;
+ }
+
+ for (; start_cpu <= end_cpu; start_cpu++) {
+ /* check for duplicates */
+ for (i = 0; i < nr_cpus; i++)
+ if (cpumap[i] == (int)start_cpu)
+ goto invalid;
+
+ assert(nr_cpus < MAX_NR_CPUS);
+ cpumap[nr_cpus++] = (int)start_cpu;
+ }
+ if (*p)
+ ++p;
+
+ cpu_list = p;
+ }
+ if (nr_cpus > 0)
+ return nr_cpus;
+
+ return default_cpu_map();
+invalid:
+ return -1;
+}