From: Adrian Hunter <adrian.hun...@intel.com>
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.hun...@intel.com>
---
tools/perf/util/evlist.c | 3 +--
tools/perf/util/util.c | 19 +++++++++++++++++++
tools/perf/util/util.h | 3 +++
3 files changed, 23 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 7bb6ee1..50fadde 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1189,8 +1189,7 @@ 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 bae8756..3aed4af 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>
/*
@@ -482,3 +484,20 @@ int filename__read_str(const char *filename, char **buf,
size_t *sizep)
close(fd);
return err;
}
+
+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 adb39f2..4b6b260 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -309,4 +309,7 @@ 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);
+
#endif /* GIT_COMPAT_UTIL_H */
--
1.8.5.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
