perf tool: Add cgroup support

This patch adds the ability to filter monitoring based on container groups
(cgroups) for both perf stat and perf record. It is possible to monitor
multiple cgroup in parallel. There is one cgroup per event. The cgroups to
monitor are passed via a new -G option followed by a comma separated list of
cgroup names.

The cgroup filesystem has to be mounted. Given a cgroup name, the perf tool
finds the corresponding directory in the cgroup filesystem and opens it. It
then passes that file descriptor to the kernel.

Example:

$ perf stat -B -a -e cycles:u,cycles:u,cycles:u -G test1,,test2 -- sleep 1
 Performance counter stats for 'sleep 1':

      2,368,667,414  cycles                   test1
      2,369,661,459  cycles
      <not counted>  cycles                   test2

        1.001856890  seconds time elapsed

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4d590290.825bdf0a.7d0a.4890@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 32 insertions, 8 deletions

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 806a9998fcd5..21c025222496 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -390,6 +390,9 @@ static void nsec_printout(int cpu, struct perf_evsel *evsel, double avg)
 
         fprintf(stderr, fmt, cpustr, msecs, csv_sep, event_name(evsel));
 
+        if (evsel->cgrp)
+                fprintf(stderr, "%s%s", csv_sep, evsel->cgrp->name);
+
         if (csv_output)
                 return;
 
@@ -420,6 +423,9 @@ static void abs_printout(int cpu, struct perf_evsel *evsel, double avg)
 
         fprintf(stderr, fmt, cpustr, avg, csv_sep, event_name(evsel));
 
+        if (evsel->cgrp)
+                fprintf(stderr, "%s%s", csv_sep, evsel->cgrp->name);
+
         if (csv_output)
                 return;
 
@@ -460,9 +466,17 @@ static void print_counter_aggr(struct perf_evsel *counter)
         int scaled = counter->counts->scaled;
 
         if (scaled == -1) {
-                fprintf(stderr, "%*s%s%-24s\n",
+                fprintf(stderr, "%*s%s%*s",
                         csv_output ? 0 : 18,
-                        "<not counted>", csv_sep, event_name(counter));
+                        "<not counted>",
+                        csv_sep,
+                        csv_output ? 0 : -24,
+                        event_name(counter));
+
+                if (counter->cgrp)
+                        fprintf(stderr, "%s%s", csv_sep, counter->cgrp->name);
+
+                fputc('\n', stderr);
                 return;
         }
 
@@ -487,7 +501,6 @@ static void print_counter_aggr(struct perf_evsel *counter)
                 fprintf(stderr, "  (scaled from %.2f%%)",
                                 100 * avg_running / avg_enabled);
         }
-
         fprintf(stderr, "\n");
 }
 
@@ -505,14 +518,18 @@ static void print_counter(struct perf_evsel *counter)
                 ena = counter->counts->cpu[cpu].ena;
                 run = counter->counts->cpu[cpu].run;
                 if (run == 0 || ena == 0) {
-                        fprintf(stderr, "CPU%*d%s%*s%s%-24s",
+                        fprintf(stderr, "CPU%*d%s%*s%s%*s",
                                 csv_output ? 0 : -4,
                                 evsel_list->cpus->map[cpu], csv_sep,
                                 csv_output ? 0 : 18,
                                 "<not counted>", csv_sep,
+                                csv_output ? 0 : -24,
                                 event_name(counter));
 
-                        fprintf(stderr, "\n");
+                        if (counter->cgrp)
+                                fprintf(stderr, "%s%s", csv_sep, counter->cgrp->name);
+
+                        fputc('\n', stderr);
                         continue;
                 }
 
@@ -529,7 +546,7 @@ static void print_counter(struct perf_evsel *counter)
                                         100.0 * run / ena);
                         }
                 }
-                fprintf(stderr, "\n");
+                fputc('\n', stderr);
         }
 }
 
@@ -642,6 +659,9 @@ static const struct option options[] = {
                     "disable CPU count aggregation"),
         OPT_STRING('x', "field-separator", &csv_sep, "separator",
                    "print counts with custom separator"),
+        OPT_CALLBACK('G', "cgroup", &evsel_list, "name",
+                     "monitor event in cgroup name only",
+                     parse_cgroups),
         OPT_END()
 };
 
@@ -682,9 +702,13 @@ int cmd_stat(int argc, const char **argv, const char *prefix __used)
         if (run_count <= 0)
                 usage_with_options(stat_usage, options);
 
-        /* no_aggr is for system-wide only */
-        if (no_aggr && !system_wide)
+        /* no_aggr, cgroup are for system-wide only */
+        if ((no_aggr || nr_cgroups) && !system_wide) {
+                fprintf(stderr, "both cgroup and no-aggregation "
+                        "modes only available in system-wide mode\n");
+
                 usage_with_options(stat_usage, options);
+        }
 
         /* Set attrs and nr_counters if no event is selected and !null_run */
         if (!null_run && !evsel_list->nr_entries) {