tools/offcputime Filter out negative offcpu duration

drcwr · Jan 15, 2021 · 2b97264 · 2b97264
1 parent a9f9769
commit 2b97264
Showing 1 changed file with 6 additions and 1 deletion.
diff --git a/tools/offcputime.py b/tools/offcputime.py
@@ -146,8 +146,13 @@ def signal_ignore(signal, frame):
  }
 
  // calculate current thread's delta time
- u64 delta = bpf_ktime_get_ns() - *tsp;
+ u64 t_start = *tsp;
+ u64 t_end = bpf_ktime_get_ns();
  start.delete(&pid);
+ if (t_start > t_end) {
+ return 0;
+ }
+ u64 delta = t_end - t_start;
  delta = delta / 1000;
  if ((delta < MINBLOCK_US) || (delta > MAXBLOCK_US)) {
  return 0;