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authorAdrian Hunter <adrian.hunter@intel.com>2013-12-11 14:36:23 +0200
committerArnaldo Carvalho de Melo <acme@redhat.com>2013-12-13 10:30:20 -0300
commit1a47245d2f3bf6276c95cd37901b562962d6ae47 (patch)
tree0df8a19d1170beaea788b629c7cff52201a80cae /tools/perf/util/util.c
parentc506c96b61fa96c9a52ad4d25e895e45c1692650 (diff)
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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@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1386765443-26966-12-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/util.c')
-rw-r--r--tools/perf/util/util.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 4a57609c0b43..8f63dba212d7 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;
+}