diff --git a/drm/ResourceManager.cpp b/drm/ResourceManager.cpp
index 789eca3..b294180 100644
--- a/drm/ResourceManager.cpp
+++ b/drm/ResourceManager.cpp
@@ -21,6 +21,7 @@
 #include <fcntl.h>
 #include <sys/stat.h>
 
+#include <ctime>
 #include <sstream>
 
 #include "bufferinfo/BufferInfoGetter.h"
@@ -114,6 +115,13 @@
   return ret;
 }
 
+auto ResourceManager::GetTimeMonotonicNs() -> int64_t {
+  struct timespec ts {};
+  clock_gettime(CLOCK_MONOTONIC, &ts);
+  constexpr int64_t kNsInSec = 1000000000LL;
+  return int64_t(ts.tv_sec) * kNsInSec + int64_t(ts.tv_nsec);
+}
+
 void ResourceManager::UpdateFrontendDisplays() {
   auto ordered_connectors = GetOrderedConnectors();