tools: Flush stdout explicitly in event loop

tools/compactsnoop.py

@@ -18,6 +18,7 @@
 import argparse
 import platform
 from datetime import datetime, timedelta
+import sys
 
 # arguments
 examples = """examples:
@@ -390,6 +391,8 @@ def print_event(cpu, data, size):
  print("\t%s" % sym)
  print("")
 
+ sys.stdout.flush()
+
 # loop with callback to print_event
 b["events"].open_perf_buffer(print_event, page_cnt=64)
 start_time = datetime.now()

tools/drsnoop.py

@@ -20,6 +20,7 @@
 from datetime import datetime, timedelta
 import os
 import math
+import sys
 
 # symbols
 kallsyms = "/proc/kallsyms"
@@ -224,6 +225,8 @@ def print_event(cpu, data, size):
  else:
  print("")
 
+ sys.stdout.flush()
+
 
 # loop with callback to print_event
 b["events"].open_perf_buffer(print_event, page_cnt=64)

tools/hardirqs.py

@@ -19,6 +19,7 @@
 from bcc import BPF
 from time import sleep, strftime
 import argparse
+import sys
 
 # arguments
 examples = """examples:
@@ -248,6 +249,8 @@
  print("%-26s %11d" % (k.name.decode('utf-8', 'replace'), v.value / factor))
  dist.clear()
 
+ sys.stdout.flush()
+
  countdown -= 1
  if exiting or countdown == 0:
  exit()

tools/mountsnoop.py

@@ -420,6 +420,7 @@ def print_event(mounts, umounts, parent, cpu, data, size):
  print('{:16} {:<7} {:<7} {:<11} {}'.format(
  syscall['comm'].decode('utf-8', 'replace'), syscall['tgid'],
  syscall['pid'], syscall['mnt_ns'], call))
+ sys.stdout.flush()
  except KeyError:
  # This might happen if we lost an event.
  pass

tools/softirqs.py

@@ -17,6 +17,7 @@
 from bcc import BPF
 from time import sleep, strftime
 import argparse
+import sys
 
 # arguments
 examples = """examples:
@@ -175,6 +176,8 @@ def vec_to_name(vec):
  print("%-16s %11d" % (vec_to_name(k.vec), v.value / factor))
  dist.clear()
 
+ sys.stdout.flush()
+
  countdown -= 1
  if exiting or countdown == 0:
  exit()

tools/syncsnoop.py

@@ -15,6 +15,7 @@
 
 from __future__ import print_function
 from bcc import BPF
+import sys
 
 # load BPF program
 b = BPF(text="""
@@ -40,6 +41,7 @@
 def print_event(cpu, data, size):
  event = b["events"].event(data)
  print("%-18.9f sync()" % (float(event.ts) / 1000000))
+ sys.stdout.flush()
 
 # loop with callback to print_event
 b["events"].open_perf_buffer(print_event)