perf script: Autopep8 futex-contention

10 years leaves its mark! Python has evolved and so has its style guide.
Even with vim it is getting hard to follow the no longer valid
guidelines (spaces vs. tabs).

Autopep8 this code to modernize it!

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
Link: http://lore.kernel.org/lkml/20200921201928.799498-1-hagen@jauu.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/scripts/python/futex-contention.py

@@ -12,8 +12,10 @@
 
 from __future__ import print_function
 
-import os, sys
-sys.path.append(os.environ['PERF_EXEC_PATH'] + '/scripts/python/Perf-Trace-Util/lib/Perf/Trace')
+import os
+import sys
+sys.path.append(os.environ['PERF_EXEC_PATH'] +
+                '/scripts/python/Perf-Trace-Util/lib/Perf/Trace')
 from Util import *
 
 process_names = {}
@@ -23,6 +25,7 @@ thread_blocktime = {}
 lock_waits = {}  # long-lived stats on (tid,lock) blockage elapsed time
 process_names = {}  # long-lived pid-to-execname mapping
 
+
 def syscalls__sys_enter_futex(event, ctxt, cpu, s, ns, tid, comm, callchain,
                               nr, uaddr, op, val, utime, uaddr2, val3):
     cmd = op & FUTEX_CMD_MASK
@@ -33,6 +36,7 @@ def syscalls__sys_enter_futex(event, ctxt, cpu, s, ns, tid, comm, callchain,
     thread_thislock[tid] = uaddr
     thread_blocktime[tid] = nsecs(s, ns)
 
+
 def syscalls__sys_exit_futex(event, ctxt, cpu, s, ns, tid, comm, callchain,
                              nr, ret):
     if tid in thread_blocktime:
@@ -41,12 +45,13 @@ def syscalls__sys_exit_futex(event, ctxt, cpu, s, ns, tid, comm, callchain,
         del thread_blocktime[tid]
         del thread_thislock[tid]
 
+
 def trace_begin():
     print("Press control+C to stop and show the summary")
 
+
 def trace_end():
     for (tid, lock) in lock_waits:
         min, max, avg, count = lock_waits[tid, lock]
         print("%s[%d] lock %x contended %d times, %d avg ns" %
               (process_names[tid], tid, lock, count, avg))
-