Commit-ID: 1a47245d2f3bf6276c95cd37901b562962d6ae47
Gitweb: http://git.kernel.org/tip/1a47245d2f3bf6276c95cd37901b562962d6ae47
Author: Adrian Hunter <adrian.hunter@xxxxxxxxx>
AuthorDate: Wed, 11 Dec 2013 14:36:23 +0200
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Fri, 13 Dec 2013 10:30:20 -0300
perf tools: Add perf_event_paranoid()
Add a function to return the value of
/proc/sys/kernel/perf_event_paranoid.
This will be used to determine default values for mmap size because perf
is not subject to mmap limits when perf_event_paranoid is less than
zero.
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1386765443-26966-12-git-send-email-alexander.shishkin@xxxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/evlist.c | 3 +--
tools/perf/util/util.c | 19 +++++++++++++++++++
tools/perf/util/util.h | 1 +
3 files changed, 21 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index af25055..2eb7378 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1191,8 +1191,7 @@ int perf_evlist__strerror_open(struct perf_evlist *evlist __maybe_unused,
"Error:\t%s.\n"
"Hint:\tCheck /proc/sys/kernel/perf_event_paranoid setting.", emsg);
- if (filename__read_int("/proc/sys/kernel/perf_event_paranoid", &value))
- break;
+ value = perf_event_paranoid();
printed += scnprintf(buf + printed, size - printed, "\nHint:\t");
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 4a57609..8f63dba 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -1,5 +1,6 @@
#include "../perf.h"
#include "util.h"
+#include "fs.h"
#include <sys/mman.h>
#ifdef HAVE_BACKTRACE_SUPPORT
#include <execinfo.h>
@@ -8,6 +9,7 @@
#include <stdlib.h>
#include <string.h>
#include <errno.h>
+#include <limits.h>
#include <linux/kernel.h>
/*
@@ -496,3 +498,20 @@ const char *get_filename_for_perf_kvm(void)
return filename;
}
+
+int perf_event_paranoid(void)
+{
+ char path[PATH_MAX];
+ const char *procfs = procfs__mountpoint();
+ int value;
+
+ if (!procfs)
+ return INT_MAX;
+
+ scnprintf(path, PATH_MAX, "%s/sys/kernel/perf_event_paranoid", procfs);
+
+ if (filename__read_int(path, &value))
+ return INT_MAX;
+
+ return value;
+}
diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index 0171213..1e7d413 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -321,6 +321,7 @@ void free_srcline(char *srcline);
int filename__read_int(const char *filename, int *value);
int filename__read_str(const char *filename, char **buf, size_t *sizep);
+int perf_event_paranoid(void);
const char *get_filename_for_perf_kvm(void);
#endif /* GIT_COMPAT_UTIL_H */
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