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authorKan Liang <kan.liang@linux.intel.com>2020-02-25 00:59:22 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2020-03-10 20:46:19 +0300
commit2a14c1bf017f48a17c8c0ba26a22625363e77cc7 (patch)
tree616467e12bc8df3f3196c7b938498b7f459f8c83 /tools/perf/util/util.c
parentf742634ab47f59160a85ddc502418556b21953c2 (diff)
downloadlinux-2a14c1bf017f48a17c8c0ba26a22625363e77cc7.tar.xz
perf util: Factor out sysctl__nmi_watchdog_enabled()
The NMI watchdog status is required for metric group constraint examination. Factor out sysctl__nmi_watchdog_enabled() to retrieve the NMI watchdog status. Users may count more than one metric group each time. If so, the NMI watchdog status may be retrieved several times. To reduce the overhead, cache the NMI watchdog status. Replace the NMI watchdog status checking in print_footer() by sysctl__nmi_watchdog_enabled(). Suggested-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jin Yao <yao.jin@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Link: http://lore.kernel.org/lkml/1582581564-184429-4-git-send-email-kan.liang@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.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 969ae560dad9..d707c9624dd9 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -55,6 +55,24 @@ int sysctl__max_stack(void)
return sysctl_perf_event_max_stack;
}
+bool sysctl__nmi_watchdog_enabled(void)
+{
+ static bool cached;
+ static bool nmi_watchdog;
+ int value;
+
+ if (cached)
+ return nmi_watchdog;
+
+ if (sysctl__read_int("kernel/nmi_watchdog", &value) < 0)
+ return false;
+
+ nmi_watchdog = (value > 0) ? true : false;
+ cached = true;
+
+ return nmi_watchdog;
+}
+
bool test_attr__enabled;
bool perf_host = true;