perf evsel: Steal the counter reading routines from stat

Making them hopefully generic enough to be used in 'perf test',
well see.

Cc: Frederic 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: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

3 files changed, 196 insertions, 92 deletions

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 589ba3a9242..a8b00b44b3c 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -93,12 +93,6 @@ static const char		*cpu_list;
 static const char               *csv_sep                        = NULL;
 static bool                     csv_output                      = false;
 
-struct cpu_counts {
-        u64 val;
-        u64 ena;
-        u64 run;
-};
-
 static volatile int done = 0;
 
 struct stats
@@ -108,15 +102,11 @@ struct stats
 
 struct perf_stat {
         struct stats      res_stats[3];
-        int               scaled;
-        struct cpu_counts cpu_counts[];
 };
 
-static int perf_evsel__alloc_stat_priv(struct perf_evsel *evsel, int ncpus)
+static int perf_evsel__alloc_stat_priv(struct perf_evsel *evsel)
 {
-        size_t priv_size = (sizeof(struct perf_stat) +
-                            (ncpus * sizeof(struct cpu_counts)));
-        evsel->priv = zalloc(priv_size);
+        evsel->priv = zalloc(sizeof(struct perf_stat));
         return evsel->priv == NULL ? -ENOMEM : 0;
 }
 
@@ -238,52 +228,14 @@ static inline int nsec_counter(struct perf_evsel *evsel)
  * Read out the results of a single counter:
  * aggregate counts across CPUs in system-wide mode
  */
-static void read_counter_aggr(struct perf_evsel *counter)
+static int read_counter_aggr(struct perf_evsel *counter)
 {
         struct perf_stat *ps = counter->priv;
-        u64 count[3], single_count[3];
-        int cpu;
-        size_t res, nv;
-        int scaled;
-        int i, thread;
-
-        count[0] = count[1] = count[2] = 0;
-
-        nv = scale ? 3 : 1;
-        for (cpu = 0; cpu < nr_cpus; cpu++) {
-                for (thread = 0; thread < thread_num; thread++) {
-                        if (FD(counter, cpu, thread) < 0)
-                                continue;
-
-                        res = read(FD(counter, cpu, thread),
-                                        single_count, nv * sizeof(u64));
-                        assert(res == nv * sizeof(u64));
-
-                        close(FD(counter, cpu, thread));
-                        FD(counter, cpu, thread) = -1;
-
-                        count[0] += single_count[0];
-                        if (scale) {
-                                count[1] += single_count[1];
-                                count[2] += single_count[2];
-                        }
-                }
-        }
-
-        scaled = 0;
-        if (scale) {
-                if (count[2] == 0) {
-                        ps->scaled = -1;
-                        count[0] = 0;
-                        return;
-                }
+        u64 *count = counter->counts->aggr.values;
+        int i;
 
-                if (count[2] < count[1]) {
-                        ps->scaled = 1;
-                        count[0] = (unsigned long long)
-                                ((double)count[0] * count[1] / count[2] + 0.5);
-                }
-        }
+        if (__perf_evsel__read(counter, nr_cpus, thread_num, scale) < 0)
+                return -1;
 
         for (i = 0; i < 3; i++)
                 update_stats(&ps->res_stats[i], count[i]);
@@ -302,46 +254,24 @@ static void read_counter_aggr(struct perf_evsel *counter)
                 update_stats(&runtime_cycles_stats[0], count[0]);
         if (perf_evsel__match(counter, HARDWARE, HW_BRANCH_INSTRUCTIONS))
                 update_stats(&runtime_branches_stats[0], count[0]);
+
+        return 0;
 }
 
 /*
  * Read out the results of a single counter:
  * do not aggregate counts across CPUs in system-wide mode
  */
-static void read_counter(struct perf_evsel *counter)
+static int read_counter(struct perf_evsel *counter)
 {
-        struct cpu_counts *cpu_counts = counter->priv;
-        u64 count[3];
+        u64 *count;
         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 (__perf_evsel__read_on_cpu(counter, cpu, 0, scale) < 0)
+                        return -1;
 
-                if (FD(counter, cpu, 0) < 0)
-                        continue;
-
-                res = read(FD(counter, cpu, 0), count, nv * sizeof(u64));
-
-                assert(res == nv * sizeof(u64));
-
-                close(FD(counter, cpu, 0));
-                FD(counter, cpu, 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].val = count[0]; /* scaled count */
-                cpu_counts[cpu].ena = count[1];
-                cpu_counts[cpu].run = count[2];
+                count = counter->counts->cpu[cpu].values;
 
                 if (perf_evsel__match(counter, SOFTWARE, SW_TASK_CLOCK))
                         update_stats(&runtime_nsecs_stats[cpu], count[0]);
@@ -350,6 +280,8 @@ static void read_counter(struct perf_evsel *counter)
                 if (perf_evsel__match(counter, HARDWARE, HW_BRANCH_INSTRUCTIONS))
                         update_stats(&runtime_branches_stats[cpu], count[0]);
         }
+
+        return 0;
 }
 
 static int run_perf_stat(int argc __used, const char **argv)
@@ -449,12 +381,17 @@ static int run_perf_stat(int argc __used, const char **argv)
         update_stats(&walltime_nsecs_stats, t1 - t0);
 
         if (no_aggr) {
-                list_for_each_entry(counter, &evsel_list, node)
+                list_for_each_entry(counter, &evsel_list, node) {
                         read_counter(counter);
+                        perf_evsel__close_fd(counter, nr_cpus, 1);
+                }
         } else {
-                list_for_each_entry(counter, &evsel_list, node)
+                list_for_each_entry(counter, &evsel_list, node) {
                         read_counter_aggr(counter);
+                        perf_evsel__close_fd(counter, nr_cpus, thread_num);
+                }
         }
+
         return WEXITSTATUS(status);
 }
 
@@ -550,7 +487,7 @@ static void print_counter_aggr(struct perf_evsel *counter)
 {
         struct perf_stat *ps = counter->priv;
         double avg = avg_stats(&ps->res_stats[0]);
-        int scaled = ps->scaled;
+        int scaled = counter->counts->scaled;
 
         if (scaled == -1) {
                 fprintf(stderr, "%*s%s%-24s\n",
@@ -590,14 +527,13 @@ static void print_counter_aggr(struct perf_evsel *counter)
  */
 static void print_counter(struct perf_evsel *counter)
 {
-        struct perf_stat *ps = counter->priv;
         u64 ena, run, val;
         int cpu;
 
         for (cpu = 0; cpu < nr_cpus; cpu++) {
-                val = ps->cpu_counts[cpu].val;
-                ena = ps->cpu_counts[cpu].ena;
-                run = ps->cpu_counts[cpu].run;
+                val = counter->counts->cpu[cpu].val;
+                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",
                                 csv_output ? 0 : -4,
@@ -818,7 +754,8 @@ int cmd_stat(int argc, const char **argv, const char *prefix __used)
         }
 
         list_for_each_entry(pos, &evsel_list, node) {
-                if (perf_evsel__alloc_stat_priv(pos, nr_cpus) < 0 ||
+                if (perf_evsel__alloc_stat_priv(pos) < 0 ||
+                    perf_evsel__alloc_counts(pos, nr_cpus) < 0 ||
                     perf_evsel__alloc_fd(pos, nr_cpus, thread_num) < 0)
                         goto out_free_fd;
         }
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 6539ec912c7..3f5de519623 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1,6 +1,8 @@
 #include "evsel.h"
 #include "util.h"
 
+#define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
+
 struct perf_evsel *perf_evsel__new(u32 type, u64 config, int idx)
 {
         struct perf_evsel *evsel = zalloc(sizeof(*evsel));
@@ -21,15 +23,101 @@ int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
         return evsel->fd != NULL ? 0 : -ENOMEM;
 }
 
+int perf_evsel__alloc_counts(struct perf_evsel *evsel, int ncpus)
+{
+        evsel->counts = zalloc((sizeof(*evsel->counts) +
+                                (ncpus * sizeof(struct perf_counts_values))));
+        return evsel->counts != NULL ? 0 : -ENOMEM;
+}
+
 void perf_evsel__free_fd(struct perf_evsel *evsel)
 {
         xyarray__delete(evsel->fd);
         evsel->fd = NULL;
 }
 
+void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
+{
+        int cpu, thread;
+
+        for (cpu = 0; cpu < ncpus; cpu++)
+                for (thread = 0; thread < nthreads; ++thread) {
+                        close(FD(evsel, cpu, thread));
+                        FD(evsel, cpu, thread) = -1;
+                }
+}
+
 void perf_evsel__delete(struct perf_evsel *evsel)
 {
         assert(list_empty(&evsel->node));
         xyarray__delete(evsel->fd);
         free(evsel);
 }
+
+int __perf_evsel__read_on_cpu(struct perf_evsel *evsel,
+                              int cpu, int thread, bool scale)
+{
+        struct perf_counts_values count;
+        size_t nv = scale ? 3 : 1;
+
+        if (FD(evsel, cpu, thread) < 0)
+                return -EINVAL;
+
+        if (readn(FD(evsel, cpu, thread), &count, nv * sizeof(u64)) < 0)
+                return -errno;
+
+        if (scale) {
+                if (count.run == 0)
+                        count.val = 0;
+                else if (count.run < count.ena)
+                        count.val = (u64)((double)count.val * count.ena / count.run + 0.5);
+        } else
+                count.ena = count.run = 0;
+
+        evsel->counts->cpu[cpu] = count;
+        return 0;
+}
+
+int __perf_evsel__read(struct perf_evsel *evsel,
+                       int ncpus, int nthreads, bool scale)
+{
+        size_t nv = scale ? 3 : 1;
+        int cpu, thread;
+        struct perf_counts_values *aggr = &evsel->counts->aggr, count;
+
+        aggr->val = 0;
+
+        for (cpu = 0; cpu < ncpus; cpu++) {
+                for (thread = 0; thread < nthreads; thread++) {
+                        if (FD(evsel, cpu, thread) < 0)
+                                continue;
+
+                        if (readn(FD(evsel, cpu, thread),
+                                  &count, nv * sizeof(u64)) < 0)
+                                return -errno;
+
+                        aggr->val += count.val;
+                        if (scale) {
+                                aggr->ena += count.ena;
+                                aggr->run += count.run;
+                        }
+                }
+        }
+
+        evsel->counts->scaled = 0;
+        if (scale) {
+                if (aggr->run == 0) {
+                        evsel->counts->scaled = -1;
+                        aggr->val = 0;
+                        return 0;
+                }
+
+                if (aggr->run < aggr->ena) {
+                        evsel->counts->scaled = 1;
+                        aggr->val = (u64)((double)aggr->val * aggr->ena / aggr->run + 0.5);
+                }
+        } else
+                aggr->ena = aggr->run = 0;
+
+        return 0;
+}
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 8a5cfb65667..8b48ef1e672 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -2,15 +2,34 @@
 #define __PERF_EVSEL_H 1
 
 #include <linux/list.h>
+#include <stdbool.h>
 #include <linux/perf_event.h>
 #include "types.h"
 #include "xyarray.h"
+ 
+struct perf_counts_values {
+        union {
+                struct {
+                        u64 val;
+                        u64 ena;
+                        u64 run;
+                };
+                u64 values[3];
+        };
+};
+
+struct perf_counts {
+        s8                        scaled;
+        struct perf_counts_values aggr;
+        struct perf_counts_values cpu[];
+};
 
 struct perf_evsel {
         struct list_head        node;
         struct perf_event_attr  attr;
         char                    *filter;
         struct xyarray          *fd;
+        struct perf_counts      *counts;
         int                     idx;
         void                    *priv;
 };
@@ -19,10 +38,70 @@ struct perf_evsel *perf_evsel__new(u32 type, u64 config, int idx);
 void perf_evsel__delete(struct perf_evsel *evsel);
 
 int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads);
+int perf_evsel__alloc_counts(struct perf_evsel *evsel, int ncpus);
 void perf_evsel__free_fd(struct perf_evsel *evsel);
+void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads);
 
 #define perf_evsel__match(evsel, t, c)          \
         (evsel->attr.type == PERF_TYPE_##t &&   \
          evsel->attr.config == PERF_COUNT_##c)
 
+int __perf_evsel__read_on_cpu(struct perf_evsel *evsel,
+                              int cpu, int thread, bool scale);
+
+/**
+ * perf_evsel__read_on_cpu - Read out the results on a CPU and thread
+ *
+ * @evsel - event selector to read value
+ * @cpu - CPU of interest
+ * @thread - thread of interest
+ */
+static inline int perf_evsel__read_on_cpu(struct perf_evsel *evsel,
+                                          int cpu, int thread)
+{
+        return __perf_evsel__read_on_cpu(evsel, cpu, thread, false);
+}
+
+/**
+ * perf_evsel__read_on_cpu_scaled - Read out the results on a CPU and thread, scaled
+ *
+ * @evsel - event selector to read value
+ * @cpu - CPU of interest
+ * @thread - thread of interest
+ */
+static inline int perf_evsel__read_on_cpu_scaled(struct perf_evsel *evsel,
+                                                 int cpu, int thread)
+{
+        return __perf_evsel__read_on_cpu(evsel, cpu, thread, true);
+}
+
+int __perf_evsel__read(struct perf_evsel *evsel, int ncpus, int nthreads,
+                       bool scale);
+
+/**
+ * perf_evsel__read - Read the aggregate results on all CPUs
+ *
+ * @evsel - event selector to read value
+ * @ncpus - Number of cpus affected, from zero
+ * @nthreads - Number of threads affected, from zero
+ */
+static inline int perf_evsel__read(struct perf_evsel *evsel,
+                                    int ncpus, int nthreads)
+{
+        return __perf_evsel__read(evsel, ncpus, nthreads, false);
+}
+
+/**
+ * perf_evsel__read_scaled - Read the aggregate results on all CPUs, scaled
+ *
+ * @evsel - event selector to read value
+ * @ncpus - Number of cpus affected, from zero
+ * @nthreads - Number of threads affected, from zero
+ */
+static inline int perf_evsel__read_scaled(struct perf_evsel *evsel,
+                                          int ncpus, int nthreads)
+{
+        return __perf_evsel__read(evsel, ncpus, nthreads, true);
+}
+
 #endif /* __PERF_EVSEL_H */