Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes:

User visible changes:

  - By default use the most precise "cycles" hw counter available, i.e.
    when the user doesn't specify any event, it will try using cycles:ppp,
    cycles:pp, etc. (Arnaldo Carvalho de Melo)

  - Remove blank lines, headers when piping output in 'perf list', so that it can
    be sanely used with 'wc -l', etc. (Arnaldo Carvalho de Melo)

  - Amend documentation about max_stack and synthesized callchains. (Adrian Hunter)

  - Fix 'perf probe -l' for probes added to kernel module functions. (Masami Hiramatsu)

Build fixes:

  - Fix shadowed declarations that break the build on older distros. (Jiri Olsa)

  - Fix build break on powerpc due to sample_reg_masks. (Sukadev Bhattiprolu)

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

1 files changed, 19 insertions, 3 deletions

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 89546228b8ed..e7e195d867ea 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -205,6 +205,20 @@ void perf_evlist__set_leader(struct perf_evlist *evlist)
 	}
 }
 
+static void perf_event_attr__set_max_precise_ip(struct perf_event_attr *attr)
+{
+	attr->precise_ip = 3;
+
+	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;
+	}
+}
+
 int perf_evlist__add_default(struct perf_evlist *evlist)
 {
 	struct perf_event_attr attr = {
@@ -215,13 +229,15 @@ int perf_evlist__add_default(struct perf_evlist *evlist)
 
 	event_attr_init(&attr);
 
+	perf_event_attr__set_max_precise_ip(&attr);
+
 	evsel = perf_evsel__new(&attr);
 	if (evsel == NULL)
 		goto error;
 
-	/* use strdup() because free(evsel) assumes name is allocated */
-	evsel->name = strdup("cycles");
-	if (!evsel->name)
+	/* use asprintf() because free(evsel) assumes name is allocated */
+	if (asprintf(&evsel->name, "cycles%.*s",
+		     attr.precise_ip ? attr.precise_ip + 1 : 0, ":ppp") < 0)
 		goto error_free;
 
 	perf_evlist__add(evlist, evsel);