scripts/kvm/kvm_stat: Cleanup of multiple imports

Removed multiple imports of the same module and moved all imports to
the top.

It is not necessary to import a module each time one of its
functions/classes is used.
For readability each import should get its own line.

Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Message-Id: <1452525484-32309-2-git-send-email-frankja@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

scripts/kvm/kvm_stat

@@ -12,8 +12,16 @@
 # the COPYING file in the top-level directory.
 
 import curses
-import sys, os, time, optparse, ctypes
+import sys
-from ctypes import *
+import os
+import time
+import optparse
+import ctypes
+import fcntl
+import resource
+import struct
+import re
+from collections import defaultdict
 
 class DebugfsProvider(object):
     def __init__(self):
@@ -285,12 +293,10 @@ filters['kvm_userspace_exit'] = ('reason', invert(userspace_exit_reasons))
 if exit_reasons:
     filters['kvm_exit'] = ('exit_reason', invert(exit_reasons))
 
-import struct, array
-
 libc = ctypes.CDLL('libc.so.6')
 syscall = libc.syscall
 get_errno = libc.__errno_location
-get_errno.restype = POINTER(c_int)
+get_errno.restype = ctypes.POINTER(ctypes.c_int)
 
 class perf_event_attr(ctypes.Structure):
     _fields_ = [('type', ctypes.c_uint32),
@@ -334,8 +340,6 @@ PERF_FORMAT_TOTAL_TIME_RUNNING  = 1 << 1
 PERF_FORMAT_ID                  = 1 << 2
 PERF_FORMAT_GROUP               = 1 << 3
 
-import re
-
 sys_tracing = '/sys/kernel/debug/tracing'
 
 class Group(object):
@@ -378,17 +382,13 @@ class Event(object):
             err = get_errno()[0]
             raise Exception('perf_event_open failed, errno = ' + err.__str__())
         if filter:
-            import fcntl
             fcntl.ioctl(fd, ioctl_numbers['SET_FILTER'], filter)
         self.fd = fd
     def enable(self):
-        import fcntl
         fcntl.ioctl(self.fd, ioctl_numbers['ENABLE'], 0)
     def disable(self):
-        import fcntl
         fcntl.ioctl(self.fd, ioctl_numbers['DISABLE'], 0)
     def reset(self):
-        import fcntl
         fcntl.ioctl(self.fd, ioctl_numbers['RESET'], 0)
 
 class TracepointProvider(object):
@@ -426,7 +426,6 @@ class TracepointProvider(object):
     def _setup(self, _fields):
         self._fields = _fields
         cpus = self._online_cpus()
-        import resource
         nfiles = len(cpus) * 1000
         resource.setrlimit(resource.RLIMIT_NOFILE, (nfiles, nfiles))
         events = []
@@ -454,7 +453,6 @@ class TracepointProvider(object):
                 else:
                     event.disable()
     def read(self):
-        from collections import defaultdict
         ret = defaultdict(int)
         for group in self.group_leaders:
             for name, val in group.read().iteritems():
@@ -468,7 +466,6 @@ class Stats:
         self._update()
     def _update(self):
         def wanted(key):
-            import re
             if not self.fields_filter:
                 return True
             return re.match(self.fields_filter, key) is not None
@@ -640,7 +637,6 @@ stats = Stats(providers, fields = options.fields)
 if options.log:
     log(stats)
 elif not options.once:
-    import curses.wrapper
     curses.wrapper(tui, stats)
 else:
     batch(stats)