Revert "tools/biolatency: Handle signals from user"

This reverts commit 87792ce.

Let us have a consensus about how bcc tools should interact with
external signals etc. before applying such changes to this tool
and other tools.

tools/biolatency.py

@@ -15,7 +15,6 @@
 from bcc import BPF
 from time import sleep, strftime
 import argparse
-import signal
 
 # arguments
 examples = """examples:
@@ -194,7 +193,15 @@ def flags_print(flags):
  desc = "NoWait-" + desc
  return desc
 
-def print_hist():
+# output
+exiting = 0 if args.interval else 1
+dist = b.get_table("dist")
+while (1):
+ try:
+ sleep(int(args.interval))
+ except KeyboardInterrupt:
+ exiting = 1
+
  print()
  if args.timestamp:
  print("%-8s\n" % strftime("%H:%M:%S"), end="")
@@ -205,28 +212,6 @@ def print_hist():
  dist.print_log2_hist(label, "disk")
  dist.clear()
 
-def exit_handler():
- print_hist()
- exit()
-
-def signal_handler(sig, frame):
- exit_handler()
-
-signal.signal(signal.SIGTERM, signal_handler)
-signal.signal(signal.SIGINT, signal_handler)
-signal.signal(signal.SIGQUIT, signal_handler)
-
-exiting = 0 if args.interval else 1
-dist = b.get_table("dist")
-
-while (1):
- try:
- sleep(int(args.interval))
- except KeyboardInterrupt:
- exiting = 1
-
- print_hist()
-
  countdown -= 1
  if exiting or countdown == 0:
- exit_handler()
+ exit()