3 files changed, 59 insertions, 44 deletions

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index ec78e93085de..6689378ee577 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -231,35 +231,6 @@ void perf_evlist__set_leader(struct perf_evlist *evlist)
         }
 }
 
-void perf_event_attr__set_max_precise_ip(struct perf_event_attr *pattr)
-{
-        struct perf_event_attr attr = {
-                .type           = PERF_TYPE_HARDWARE,
-                .config         = PERF_COUNT_HW_CPU_CYCLES,
-                .exclude_kernel = 1,
-                .precise_ip     = 3,
-        };
-
-        event_attr_init(&attr);
-
-        /*
-         * Unnamed union member, not supported as struct member named
-         * initializer in older compilers such as gcc 4.4.7
-         */
-        attr.sample_period = 1;
-
-        while (attr.precise_ip != 0) {
-                int fd = sys_perf_event_open(&attr, 0, -1, -1, 0);
-                if (fd != -1) {
-                        close(fd);
-                        break;
-                }
-                --attr.precise_ip;
-        }
-
-        pattr->precise_ip = attr.precise_ip;
-}
-
 int __perf_evlist__add_default(struct perf_evlist *evlist, bool precise)
 {
         struct perf_evsel *evsel = perf_evsel__new_cycles(precise);
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index dcb68f34d2cd..6a94785b9100 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -315,8 +315,6 @@ void perf_evlist__to_front(struct perf_evlist *evlist,
 void perf_evlist__set_tracking_event(struct perf_evlist *evlist,
                                      struct perf_evsel *tracking_evsel);
 
-void perf_event_attr__set_max_precise_ip(struct perf_event_attr *attr);
-
 struct perf_evsel *
 perf_evlist__find_evsel_by_str(struct perf_evlist *evlist, const char *str);
 
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 7835e05f0c0a..66d066f18b5b 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -295,7 +295,6 @@ struct perf_evsel *perf_evsel__new_cycles(bool precise)
         if (!precise)
                 goto new_event;
 
-        perf_event_attr__set_max_precise_ip(&attr);
         /*
          * Now let the usual logic to set up the perf_event_attr defaults
          * to kick in when we return and before perf_evsel__open() is called.
@@ -305,6 +304,8 @@ new_event:
         if (evsel == NULL)
                 goto out;
 
+        evsel->precise_max = true;
+
         /* use asprintf() because free(evsel) assumes name is allocated */
         if (asprintf(&evsel->name, "cycles%s%s%.*s",
                      (attr.precise_ip || attr.exclude_kernel) ? ":" : "",
@@ -1083,7 +1084,7 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts,
         }
 
         if (evsel->precise_max)
-                perf_event_attr__set_max_precise_ip(attr);
+                attr->precise_ip = 3;
 
         if (opts->all_user) {
                 attr->exclude_kernel = 1;
@@ -1749,6 +1750,59 @@ static bool ignore_missing_thread(struct perf_evsel *evsel,
         return true;
 }
 
+static void display_attr(struct perf_event_attr *attr)
+{
+        if (verbose >= 2) {
+                fprintf(stderr, "%.60s\n", graph_dotted_line);
+                fprintf(stderr, "perf_event_attr:\n");
+                perf_event_attr__fprintf(stderr, attr, __open_attr__fprintf, NULL);
+                fprintf(stderr, "%.60s\n", graph_dotted_line);
+        }
+}
+
+static int perf_event_open(struct perf_evsel *evsel,
+                           pid_t pid, int cpu, int group_fd,
+                           unsigned long flags)
+{
+        int precise_ip = evsel->attr.precise_ip;
+        int fd;
+
+        while (1) {
+                pr_debug2("sys_perf_event_open: pid %d  cpu %d  group_fd %d  flags %#lx",
+                          pid, cpu, group_fd, flags);
+
+                fd = sys_perf_event_open(&evsel->attr, pid, cpu, group_fd, flags);
+                if (fd >= 0)
+                        break;
+
+                /*
+                 * Do quick precise_ip fallback if:
+                 *  - there is precise_ip set in perf_event_attr
+                 *  - maximum precise is requested
+                 *  - sys_perf_event_open failed with ENOTSUP error,
+                 *    which is associated with wrong precise_ip
+                 */
+                if (!precise_ip || !evsel->precise_max || (errno != ENOTSUP))
+                        break;
+
+                /*
+                 * We tried all the precise_ip values, and it's
+                 * still failing, so leave it to standard fallback.
+                 */
+                if (!evsel->attr.precise_ip) {
+                        evsel->attr.precise_ip = precise_ip;
+                        break;
+                }
+
+                pr_debug2("\nsys_perf_event_open failed, error %d\n", -ENOTSUP);
+                evsel->attr.precise_ip--;
+                pr_debug2("decreasing precise_ip by one (%d)\n", evsel->attr.precise_ip);
+                display_attr(&evsel->attr);
+        }
+
+        return fd;
+}
+
 int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
                      struct thread_map *threads)
 {
@@ -1824,12 +1878,7 @@ retry_sample_id:
         if (perf_missing_features.sample_id_all)
                 evsel->attr.sample_id_all = 0;
 
-        if (verbose >= 2) {
-                fprintf(stderr, "%.60s\n", graph_dotted_line);
-                fprintf(stderr, "perf_event_attr:\n");
-                perf_event_attr__fprintf(stderr, &evsel->attr, __open_attr__fprintf, NULL);
-                fprintf(stderr, "%.60s\n", graph_dotted_line);
-        }
+        display_attr(&evsel->attr);
 
         for (cpu = 0; cpu < cpus->nr; cpu++) {
 
@@ -1841,13 +1890,10 @@ retry_sample_id:
 
                         group_fd = get_group_fd(evsel, cpu, thread);
 retry_open:
-                        pr_debug2("sys_perf_event_open: pid %d  cpu %d  group_fd %d  flags %#lx",
-                                  pid, cpus->map[cpu], group_fd, flags);
-
                         test_attr__ready();
 
-                        fd = sys_perf_event_open(&evsel->attr, pid, cpus->map[cpu],
-                                                 group_fd, flags);
+                        fd = perf_event_open(evsel, pid, cpus->map[cpu],
+                                             group_fd, flags);
 
                         FD(evsel, cpu, thread) = fd;