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-rw-r--r--tools/perf/util/evsel.c59
-rw-r--r--tools/perf/util/evsel.h2
2 files changed, 28 insertions, 33 deletions
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index a576d985a7a7..54d251327b5b 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1709,42 +1709,29 @@ static void display_attr(struct perf_event_attr *attr)
}
}
-static int perf_event_open(struct evsel *evsel,
- pid_t pid, int cpu, int group_fd)
+bool evsel__precise_ip_fallback(struct evsel *evsel)
{
- int precise_ip = evsel->core.attr.precise_ip;
- int fd;
-
- while (1) {
- pr_debug2_peo("sys_perf_event_open: pid %d cpu %d group_fd %d flags %#lx",
- pid, cpu, group_fd, evsel->open_flags);
-
- fd = sys_perf_event_open(&evsel->core.attr, pid, cpu, group_fd, evsel->open_flags);
- if (fd >= 0)
- break;
-
- /* Do not try less precise if not requested. */
- if (!evsel->precise_max)
- break;
-
- /*
- * We tried all the precise_ip values, and it's
- * still failing, so leave it to standard fallback.
- */
- if (!evsel->core.attr.precise_ip) {
- evsel->core.attr.precise_ip = precise_ip;
- break;
- }
+ /* Do not try less precise if not requested. */
+ if (!evsel->precise_max)
+ return false;
- pr_debug2_peo("\nsys_perf_event_open failed, error %d\n", -ENOTSUP);
- evsel->core.attr.precise_ip--;
- pr_debug2_peo("decreasing precise_ip by one (%d)\n", evsel->core.attr.precise_ip);
- display_attr(&evsel->core.attr);
+ /*
+ * We tried all the precise_ip values, and it's
+ * still failing, so leave it to standard fallback.
+ */
+ if (!evsel->core.attr.precise_ip) {
+ evsel->core.attr.precise_ip = evsel->precise_ip_original;
+ return false;
}
- return fd;
-}
+ if (!evsel->precise_ip_original)
+ evsel->precise_ip_original = evsel->core.attr.precise_ip;
+ evsel->core.attr.precise_ip--;
+ pr_debug2_peo("decreasing precise_ip by one (%d)\n", evsel->core.attr.precise_ip);
+ display_attr(&evsel->core.attr);
+ return true;
+}
static struct perf_cpu_map *empty_cpu_map;
static struct perf_thread_map *empty_thread_map;
@@ -2004,8 +1991,11 @@ retry_open:
test_attr__ready();
- fd = perf_event_open(evsel, pid, cpus->map[cpu],
- group_fd);
+ pr_debug2_peo("sys_perf_event_open: pid %d cpu %d group_fd %d flags %#lx",
+ pid, cpus->map[cpu], group_fd, evsel->open_flags);
+
+ fd = sys_perf_event_open(&evsel->core.attr, pid, cpus->map[cpu],
+ group_fd, evsel->open_flags);
FD(evsel, cpu, thread) = fd;
@@ -2058,6 +2048,9 @@ retry_open:
return 0;
try_fallback:
+ if (evsel__precise_ip_fallback(evsel))
+ goto retry_open;
+
if (evsel__ignore_missing_thread(evsel, cpus->nr, cpu, threads, thread, err)) {
/* We just removed 1 thread, so lower the upper nthreads limit. */
nthreads--;
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index b749bee2c7a6..1b3eeab5f188 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -151,6 +151,7 @@ struct evsel {
struct bperf_follower_bpf *follower_skel;
};
unsigned long open_flags;
+ int precise_ip_original;
};
struct perf_missing_features {
@@ -298,6 +299,7 @@ bool evsel__ignore_missing_thread(struct evsel *evsel,
int nr_cpus, int cpu,
struct perf_thread_map *threads,
int thread, int err);
+bool evsel__precise_ip_fallback(struct evsel *evsel);
struct perf_sample;