diff --git a/libprocessgroup/Android.mk b/libprocessgroup/Android.mk
index ee6ba58..87985d4 100644
--- a/libprocessgroup/Android.mk
+++ b/libprocessgroup/Android.mk
@@ -3,7 +3,16 @@
 include $(CLEAR_VARS)
 LOCAL_SRC_FILES := processgroup.cpp
 LOCAL_MODULE := libprocessgroup
-LOCAL_SHARED_LIBRARIES := liblog libutils
+LOCAL_STATIC_LIBRARIES := liblog
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
+LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
+LOCAL_CFLAGS := -Wall -Werror
+include $(BUILD_STATIC_LIBRARY)
+
+include $(CLEAR_VARS)
+LOCAL_SRC_FILES := processgroup.cpp
+LOCAL_MODULE := libprocessgroup
+LOCAL_SHARED_LIBRARIES := liblog
 LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
 LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
 LOCAL_CFLAGS := -Wall -Werror
diff --git a/libprocessgroup/processgroup.cpp b/libprocessgroup/processgroup.cpp
index 00a0357..da4bb71 100644
--- a/libprocessgroup/processgroup.cpp
+++ b/libprocessgroup/processgroup.cpp
@@ -22,19 +22,18 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <inttypes.h>
-#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
 #include <sys/types.h>
+
+#include <chrono>
 #include <memory>
 
 #include <log/log.h>
 #include <private/android_filesystem_config.h>
 
-#include <utils/SystemClock.h>
-
 #include <processgroup/processgroup.h>
 #include "processgroup_priv.h"
 
@@ -250,25 +249,26 @@
 
 int killProcessGroup(uid_t uid, int initialPid, int signal)
 {
-    int processes;
-    const int sleep_us = 5 * 1000;  // 5ms
-    int64_t startTime = android::uptimeMillis();
-    int retry = 40;
+    std::chrono::steady_clock::time_point start = std::chrono::steady_clock::now();
 
+    int retry = 40;
+    int processes;
     while ((processes = killProcessGroupOnce(uid, initialPid, signal)) > 0) {
         SLOGV("killed %d processes for processgroup %d\n", processes, initialPid);
         if (retry > 0) {
-            usleep(sleep_us);
+            usleep(5 * 1000); // 5ms
             --retry;
         } else {
-            SLOGE("failed to kill %d processes for processgroup %d\n",
-                    processes, initialPid);
+            SLOGE("failed to kill %d processes for processgroup %d\n", processes, initialPid);
             break;
         }
     }
 
-    SLOGV("Killed process group uid %d pid %d in %" PRId64 "ms, %d procs remain", uid, initialPid,
-            android::uptimeMillis()-startTime, processes);
+    std::chrono::steady_clock::time_point end = std::chrono::steady_clock::now();
+
+    SLOGV("Killed process group uid %d pid %d in %dms, %d procs remain", uid, initialPid,
+          static_cast<int>(std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count()),
+          processes);
 
     if (processes == 0) {
         return removeProcessGroup(uid, initialPid);