fix(bpf): exclude bpf overhead in bpf_cpu_time

Signed-off-by: Vimal Kumar <[email protected]>
sustainable-computing-io · Sep 20, 2024 · b90a63b · b90a63b
1 parent dbba3f4
commit b90a63b
Showing 1 changed file with 4 additions and 3 deletions.
diff --git a/bpf/kepler.bpf.h b/bpf/kepler.bpf.h
@@ -353,12 +353,13 @@ static inline int do_kepler_sched_switch_trace(
 		}
 	}
 
-	// Add task on-cpu running start time
-	bpf_map_update_elem(&pid_time_map, &next_pid, &curr_ts, BPF_ANY);
-
 	// create new process metrics
 	register_new_process_if_not_exist(prev_tgid);
 
+	// Add task on-cpu running start time
+	curr_ts = bpf_ktime_get_ns();
+	bpf_map_update_elem(&pid_time_map, &next_pid, &curr_ts, BPF_ANY);
+
 	return 0;
 }