perf stat: Add no-aggregation mode to -a

This patch adds a new -A option to perf stat. If specified then perf stat does
not aggregate counts across all monitored CPUs in system-wide mode, i.e., when
using -a. This option is not supported in per-thread mode.

Being able to get a per-cpu breakdown is useful to detect imbalances between
CPUs when running a uniform workload than spans all monitored CPUs.

The second version corrects the missing cpumap[] support, so that it works when
the -C option is used.

The third version fixes a missing cpumap[] in print_counter() and removes a
stray patch in builtin-trace.c.

Examples on a 4-way system:

# perf stat -a   -e cycles,instructions -- sleep 1
 Performance counter stats for 'sleep 1':
         9592808135  cycles
         3490380006  instructions             #      0.364 IPC
        1.001584632  seconds time elapsed

# perf stat -a -A -e cycles,instructions -- sleep 1
 Performance counter stats for 'sleep 1':
CPU0            2398163767  cycles
CPU1            2398180817  cycles
CPU2            2398217115  cycles
CPU3            2398247483  cycles
CPU0             872282046  instructions             #      0.364 IPC
CPU1             873481776  instructions             #      0.364 IPC
CPU2             872638127  instructions             #      0.364 IPC
CPU3             872437789  instructions             #      0.364 IPC
        1.001556052  seconds time elapsed

Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <robert.richter@amd.com>
LKML-Reference: <4ce257b5.1e07e30a.7b6b.3aa9@mx.google.com>
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 144 insertions, 25 deletions

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index a6b4d44f9502..b3e568ffad27 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -75,6 +75,7 @@ static int			run_idx				=  0;
 static int                      run_count                       =  1;
 static bool                     no_inherit                      = false;
 static bool                     scale                           =  true;
+static bool                     no_aggr                         = false;
 static pid_t                    target_pid                      = -1;
 static pid_t                    target_tid                      = -1;
 static pid_t                    *all_tids                       =  NULL;
@@ -89,6 +90,12 @@ static int			*fd[MAX_NR_CPUS][MAX_COUNTERS];
 
 static int                      event_scaled[MAX_COUNTERS];
 
+static struct {
+        u64 val;
+        u64 ena;
+        u64 run;
+} cpu_counts[MAX_NR_CPUS][MAX_COUNTERS];
+
 static volatile int done = 0;
 
 struct stats
@@ -136,10 +143,10 @@ static double stddev_stats(struct stats *stats)
 }
 
 struct stats                    event_res_stats[MAX_COUNTERS][3];
-struct stats                    runtime_nsecs_stats;
+struct stats                    runtime_nsecs_stats[MAX_NR_CPUS];
+struct stats                    runtime_cycles_stats[MAX_NR_CPUS];
+struct stats                    runtime_branches_stats[MAX_NR_CPUS];
 struct stats                    walltime_nsecs_stats;
-struct stats                    runtime_cycles_stats;
-struct stats                    runtime_branches_stats;
 
 #define MATCH_EVENT(t, c, counter)                      \
         (attrs[counter].type == PERF_TYPE_##t &&        \
@@ -205,8 +212,9 @@ static inline int nsec_counter(int counter)
 
 /*
  * Read out the results of a single counter:
+ * aggregate counts across CPUs in system-wide mode
  */
-static void read_counter(int counter)
+static void read_counter_aggr(int counter)
 {
         u64 count[3], single_count[3];
         int cpu;
@@ -264,11 +272,58 @@ static void read_counter(int counter)
          * Save the full runtime - to allow normalization during printout:
          */
         if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))
-                update_stats(&runtime_nsecs_stats, count[0]);
+                update_stats(&runtime_nsecs_stats[0], count[0]);
         if (MATCH_EVENT(HARDWARE, HW_CPU_CYCLES, counter))
-                update_stats(&runtime_cycles_stats, count[0]);
+                update_stats(&runtime_cycles_stats[0], count[0]);
         if (MATCH_EVENT(HARDWARE, HW_BRANCH_INSTRUCTIONS, counter))
-                update_stats(&runtime_branches_stats, count[0]);
+                update_stats(&runtime_branches_stats[0], count[0]);
+}
+
+/*
+ * Read out the results of a single counter:
+ * do not aggregate counts across CPUs in system-wide mode
+ */
+static void read_counter(int counter)
+{
+        u64 count[3];
+        int cpu;
+        size_t res, nv;
+
+        count[0] = count[1] = count[2] = 0;
+
+        nv = scale ? 3 : 1;
+
+        for (cpu = 0; cpu < nr_cpus; cpu++) {
+
+                if (fd[cpu][counter][0] < 0)
+                        continue;
+
+                res = read(fd[cpu][counter][0], count, nv * sizeof(u64));
+
+                assert(res == nv * sizeof(u64));
+
+                close(fd[cpu][counter][0]);
+                fd[cpu][counter][0] = -1;
+
+                if (scale) {
+                        if (count[2] == 0) {
+                                count[0] = 0;
+                        } else if (count[2] < count[1]) {
+                                count[0] = (unsigned long long)
+                                ((double)count[0] * count[1] / count[2] + 0.5);
+                        }
+                }
+                cpu_counts[cpu][counter].val = count[0]; /* scaled count */
+                cpu_counts[cpu][counter].ena = count[1];
+                cpu_counts[cpu][counter].run = count[2];
+
+                if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))
+                        update_stats(&runtime_nsecs_stats[cpu], count[0]);
+                if (MATCH_EVENT(HARDWARE, HW_CPU_CYCLES, counter))
+                        update_stats(&runtime_cycles_stats[cpu], count[0]);
+                if (MATCH_EVENT(HARDWARE, HW_BRANCH_INSTRUCTIONS, counter))
+                        update_stats(&runtime_branches_stats[cpu], count[0]);
+        }
 }
 
 static int run_perf_stat(int argc __used, const char **argv)
@@ -362,9 +417,13 @@ static int run_perf_stat(int argc __used, const char **argv)
 
         update_stats(&walltime_nsecs_stats, t1 - t0);
 
-        for (counter = 0; counter < nr_counters; counter++)
-                read_counter(counter);
-
+        if (no_aggr) {
+                for (counter = 0; counter < nr_counters; counter++)
+                        read_counter(counter);
+        } else {
+                for (counter = 0; counter < nr_counters; counter++)
+                        read_counter_aggr(counter);
+        }
         return WEXITSTATUS(status);
 }
 
@@ -377,11 +436,15 @@ static void print_noise(int counter, double avg)
                         100 * stddev_stats(&event_res_stats[counter][0]) / avg);
 }
 
-static void nsec_printout(int counter, double avg)
+static void nsec_printout(int cpu, int counter, double avg)
 {
         double msecs = avg / 1e6;
 
-        fprintf(stderr, " %18.6f  %-24s", msecs, event_name(counter));
+        if (no_aggr)
+                fprintf(stderr, "CPU%-4d %18.6f  %-24s",
+                        cpumap[cpu], msecs, event_name(counter));
+        else
+                fprintf(stderr, " %18.6f  %-24s", msecs, event_name(counter));
 
         if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter)) {
                 fprintf(stderr, " # %10.3f CPUs ",
@@ -389,33 +452,41 @@ static void nsec_printout(int counter, double avg)
         }
 }
 
-static void abs_printout(int counter, double avg)
+static void abs_printout(int cpu, int counter, double avg)
 {
         double total, ratio = 0.0;
+        char cpustr[16] = { '\0', };
+
+        if (no_aggr)
+                sprintf(cpustr, "CPU%-4d", cpumap[cpu]);
+        else
+                cpu = 0;
 
         if (big_num)
-                fprintf(stderr, " %'18.0f  %-24s", avg, event_name(counter));
+                fprintf(stderr, "%s %'18.0f  %-24s",
+                        cpustr, avg, event_name(counter));
         else
-                fprintf(stderr, " %18.0f  %-24s", avg, event_name(counter));
+                fprintf(stderr, "%s %18.0f  %-24s",
+                        cpustr, avg, event_name(counter));
 
         if (MATCH_EVENT(HARDWARE, HW_INSTRUCTIONS, counter)) {
-                total = avg_stats(&runtime_cycles_stats);
+                total = avg_stats(&runtime_cycles_stats[cpu]);
 
                 if (total)
                         ratio = avg / total;
 
                 fprintf(stderr, " # %10.3f IPC  ", ratio);
         } else if (MATCH_EVENT(HARDWARE, HW_BRANCH_MISSES, counter) &&
-                        runtime_branches_stats.n != 0) {
-                total = avg_stats(&runtime_branches_stats);
+                        runtime_branches_stats[cpu].n != 0) {
+                total = avg_stats(&runtime_branches_stats[cpu]);
 
                 if (total)
                         ratio = avg * 100 / total;
 
                 fprintf(stderr, " # %10.3f %%    ", ratio);
 
-        } else if (runtime_nsecs_stats.n != 0) {
-                total = avg_stats(&runtime_nsecs_stats);
+        } else if (runtime_nsecs_stats[cpu].n != 0) {
+                total = avg_stats(&runtime_nsecs_stats[cpu]);
 
                 if (total)
                         ratio = 1000.0 * avg / total;
@@ -426,8 +497,9 @@ static void abs_printout(int counter, double avg)
 
 /*
  * Print out the results of a single counter:
+ * aggregated counts in system-wide mode
  */
-static void print_counter(int counter)
+static void print_counter_aggr(int counter)
 {
         double avg = avg_stats(&event_res_stats[counter][0]);
         int scaled = event_scaled[counter];
@@ -439,9 +511,9 @@ static void print_counter(int counter)
         }
 
         if (nsec_counter(counter))
-                nsec_printout(counter, avg);
+                nsec_printout(-1, counter, avg);
         else
-                abs_printout(counter, avg);
+                abs_printout(-1, counter, avg);
 
         print_noise(counter, avg);
 
@@ -458,6 +530,42 @@ static void print_counter(int counter)
         fprintf(stderr, "\n");
 }
 
+/*
+ * Print out the results of a single counter:
+ * does not use aggregated count in system-wide
+ */
+static void print_counter(int counter)
+{
+        u64 ena, run, val;
+        int cpu;
+
+        for (cpu = 0; cpu < nr_cpus; cpu++) {
+                val = cpu_counts[cpu][counter].val;
+                ena = cpu_counts[cpu][counter].ena;
+                run = cpu_counts[cpu][counter].run;
+                if (run == 0 || ena == 0) {
+                        fprintf(stderr, "CPU%-4d %18s  %-24s", cpumap[cpu],
+                                        "<not counted>", event_name(counter));
+
+                        fprintf(stderr, "\n");
+                        continue;
+                }
+
+                if (nsec_counter(counter))
+                        nsec_printout(cpu, counter, val);
+                else
+                        abs_printout(cpu, counter, val);
+
+                print_noise(counter, 1.0);
+
+                if (run != ena) {
+                        fprintf(stderr, "  (scaled from %.2f%%)",
+                                        100.0 * run / ena);
+                }
+                fprintf(stderr, "\n");
+        }
+}
+
 static void print_stat(int argc, const char **argv)
 {
         int i, counter;
@@ -480,8 +588,13 @@ static void print_stat(int argc, const char **argv)
                 fprintf(stderr, " (%d runs)", run_count);
         fprintf(stderr, ":\n\n");
 
-        for (counter = 0; counter < nr_counters; counter++)
-                print_counter(counter);
+        if (no_aggr) {
+                for (counter = 0; counter < nr_counters; counter++)
+                        print_counter(counter);
+        } else {
+                for (counter = 0; counter < nr_counters; counter++)
+                        print_counter_aggr(counter);
+        }
 
         fprintf(stderr, "\n");
         fprintf(stderr, " %18.9f  seconds time elapsed",
@@ -545,6 +658,8 @@ static const struct option options[] = {
                     "print large numbers with thousands\' separators"),
         OPT_STRING('C', "cpu", &cpu_list, "cpu",
                     "list of cpus to monitor in system-wide"),
+        OPT_BOOLEAN('A', "no-aggr", &no_aggr,
+                    "disable CPU count aggregation"),
         OPT_END()
 };
 
@@ -562,6 +677,10 @@ 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)
+                usage_with_options(stat_usage, options);
+
         /* Set attrs and nr_counters if no event is selected and !null_run */
         if (!null_run && !nr_counters) {
                 memcpy(attrs, default_attrs, sizeof(default_attrs));