context_switch_latency: more diagnostics
diff --git a/context_switch_latency.c b/context_switch_latency.c
index 4b8989c..650f853 100644
--- a/context_switch_latency.c
+++ b/context_switch_latency.c
@@ -83,7 +83,7 @@
     if (!strcmp(argv[1], "1"))
       use_xstate = 1;
     else if (strcmp(argv[1], "0"))
-      abort();
+      errx(1, "first arg is wrong");
 
     if (!strcmp(argv[2], "same")) {
       main_cpu = 0;
@@ -92,7 +92,7 @@
       main_cpu = 0;
       thread_cpu = 1;
     } else {
-      abort();
+      errx(1, "second arg is wrong");
     }
   }
 
@@ -100,13 +100,13 @@
 
   to_thread = eventfd(0, 0);
   if (to_thread < 0)
-    abort();
+    err(1, "eventfd");
   from_thread = eventfd(0, 0);
   if (from_thread < 0)
-    abort();
+    err(1, "eventfd");
   
   if (pthread_create(&thread, 0, threadproc, 0) != 0)
-    abort();
+    err(1, "pthread_create");
 
   cpu_set_t cpuset;
   CPU_ZERO(&cpuset);