tools/power turbostat: Add --no-perf option

Add the --no-perf option to allow users to run turbostat without
accessing perf.

Signed-off-by: Patryk Wlazlyn <patryk.wlazlyn@linux.intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/tools/power/x86/turbostat/turbostat.8 b/tools/power/x86/turbostat/turbostat.8
index 28be452fbfe2f18e1b6d2ab3b43f0dcc24afb6bb..567327b004e687d2d0d6045f4ec59585cf3782ed 100644 (file)
--- a/tools/power/x86/turbostat/turbostat.8
+++ b/tools/power/x86/turbostat/turbostat.8
@@ -69,6 +69,8 @@ The column name "all" can be used to enable all disabled-by-default built-in cou
 .PP
 +\fB--no-msr\fP Disable all the uses of the MSR driver.
 +.PP
++\fB--no-perf\fP Disable all the uses of the perf API.
++.PP
 \fB--interval seconds\fP overrides the default 5.0 second measurement interval.
 .PP
 \fB--num_iterations num\fP number of the measurement iterations.

diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
index 4d5437a9725bf2101cc7cd5c24db48b0fc1a6de1..bad2fec7f3424a6b38ed84f1728a1178559fcec2 100644 (file)
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -267,6 +267,7 @@ unsigned int has_hwp_pkg;   /* IA32_HWP_REQUEST_PKG */
 unsigned int first_counter_read = 1;
 int ignore_stdin;
 bool no_msr;
+bool no_perf;
 
 int get_msr(int cpu, off_t offset, unsigned long long *msr);
 
@@ -1314,8 +1315,17 @@ static void bic_disable_msr_access(void)
        bic_enabled &= ~bic_msrs;
 }
 
+static void bic_disable_perf_access(void)
+{
+       const unsigned long bic_perf = BIC_IPC;
+
+       bic_enabled &= ~bic_perf;
+}
+
 static long perf_event_open(struct perf_event_attr *hw_event, pid_t pid, int cpu, int group_fd, unsigned long flags)
 {
+       assert(!no_perf);
+
        return syscall(__NR_perf_event_open, hw_event, pid, cpu, group_fd, flags);
 }
 
@@ -1332,8 +1342,8 @@ static int perf_instr_count_open(int cpu_num)
        /* counter for cpu_num, including user + kernel and all processes */
        fd = perf_event_open(&pea, -1, cpu_num, -1, 0);
        if (fd == -1) {
-               warnx("capget(CAP_PERFMON) failed, try \"# setcap cap_sys_admin=ep %s\"", progname);
-               BIC_NOT_PRESENT(BIC_IPC);
+               warnx("capget(CAP_PERFMON) failed, try \"# setcap cap_sys_admin=ep %s\" or use --no-perf", progname);
+               bic_disable_perf_access();
        }
 
        return fd;
@@ -1399,6 +1409,7 @@ void help(void)
                "  -J, --Joules displays energy in Joules instead of Watts\n"
                "  -l, --list   list column headers only\n"
                "  -M, --no-msr Disable all uses of the MSR driver\n"
+               "  -P, --no-perf Disable all uses of the perf API\n"
                "  -n, --num_iterations num\n"
                "               number of the measurement iterations\n"
                "  -N, --header_iterations num\n"
@@ -6745,6 +6756,7 @@ void cmdline(int argc, char **argv)
                { "out", required_argument, 0, 'o' },
                { "quiet", no_argument, 0, 'q' },
                { "no-msr", no_argument, 0, 'M' },
+               { "no-perf", no_argument, 0, 'P' },
                { "show", required_argument, 0, 's' },
                { "Summary", no_argument, 0, 'S' },
                { "TCC", required_argument, 0, 'T' },
@@ -6758,11 +6770,14 @@ void cmdline(int argc, char **argv)
         * Parse some options early, because they may make other options invalid,
         * like adding the MSR counter with --add and at the same time using --no-msr.
         */
-       while ((opt = getopt_long_only(argc, argv, "M", long_options, &option_index)) != -1) {
+       while ((opt = getopt_long_only(argc, argv, "MP", long_options, &option_index)) != -1) {
                switch (opt) {
                case 'M':
                        no_msr = 1;
                        break;
+               case 'P':
+                       no_perf = 1;
+                       break;
                default:
                        break;
                }
@@ -6828,6 +6843,7 @@ void cmdline(int argc, char **argv)
                        quiet = 1;
                        break;
                case 'M':
+               case 'P':
                        /* Parsed earlier */
                        break;
                case 'n':
@@ -6909,6 +6925,9 @@ skip_cgroup_setting:
        if (no_msr)
                bic_disable_msr_access();
 
+       if (no_perf)
+               bic_disable_perf_access();
+
        if (!quiet) {
                print_version();
                print_bootcmd();