tools: Add kvm_stat vm monitor script

This tool displays kvm vm exit statistics to ease vm monitoring. It
takes its data from the kvm debugfs files or the vm tracepoints and
outputs them as a curses ui or simple text.

It was moved from qemu, as it is dependent on the kernel whereas qemu
works with a large number of kernel versions, some of which may break
the script.

Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Janosch Frank 2016-05-18 13:26:21 +02:00 committed by Paolo Bonzini
parent 3ce424e454
commit f9bc9e65fb
3 changed files with 835 additions and 1 deletions

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@ -16,6 +16,7 @@ help:
@echo ' gpio - GPIO tools'
@echo ' hv - tools used when in Hyper-V clients'
@echo ' iio - IIO tools'
@echo ' kvm_stat - top-like utility for displaying kvm statistics'
@echo ' lguest - a minimal 32-bit x86 hypervisor'
@echo ' net - misc networking tools'
@echo ' perf - Linux performance measurement and analysis tool'
@ -110,10 +111,13 @@ tmon_install:
freefall_install:
$(call descend,laptop/$(@:_install=),install)
kvm_stat_install:
$(call descend,kvm/$(@:_install=),install)
install: acpi_install cgroup_install cpupower_install hv_install firewire_install lguest_install \
perf_install selftests_install turbostat_install usb_install \
virtio_install vm_install net_install x86_energy_perf_policy_install \
tmon_install freefall_install objtool_install
tmon_install freefall_install objtool_install kvm_stat_install
acpi_clean:
$(call descend,power/acpi,clean)

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@ -0,0 +1,5 @@
BINDIR=usr/bin
install:
mkdir -p $(INSTALL_ROOT)/$(BINDIR)
install -m 755 -p "kvm_stat" "$(INSTALL_ROOT)/$(BINDIR)/$(TARGET)"

825
tools/kvm/kvm_stat/kvm_stat Executable file
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@ -0,0 +1,825 @@
#!/usr/bin/python
#
# top-like utility for displaying kvm statistics
#
# Copyright 2006-2008 Qumranet Technologies
# Copyright 2008-2011 Red Hat, Inc.
#
# Authors:
# Avi Kivity <avi@redhat.com>
#
# This work is licensed under the terms of the GNU GPL, version 2. See
# the COPYING file in the top-level directory.
import curses
import sys
import os
import time
import optparse
import ctypes
import fcntl
import resource
import struct
import re
from collections import defaultdict
from time import sleep
VMX_EXIT_REASONS = {
'EXCEPTION_NMI': 0,
'EXTERNAL_INTERRUPT': 1,
'TRIPLE_FAULT': 2,
'PENDING_INTERRUPT': 7,
'NMI_WINDOW': 8,
'TASK_SWITCH': 9,
'CPUID': 10,
'HLT': 12,
'INVLPG': 14,
'RDPMC': 15,
'RDTSC': 16,
'VMCALL': 18,
'VMCLEAR': 19,
'VMLAUNCH': 20,
'VMPTRLD': 21,
'VMPTRST': 22,
'VMREAD': 23,
'VMRESUME': 24,
'VMWRITE': 25,
'VMOFF': 26,
'VMON': 27,
'CR_ACCESS': 28,
'DR_ACCESS': 29,
'IO_INSTRUCTION': 30,
'MSR_READ': 31,
'MSR_WRITE': 32,
'INVALID_STATE': 33,
'MWAIT_INSTRUCTION': 36,
'MONITOR_INSTRUCTION': 39,
'PAUSE_INSTRUCTION': 40,
'MCE_DURING_VMENTRY': 41,
'TPR_BELOW_THRESHOLD': 43,
'APIC_ACCESS': 44,
'EPT_VIOLATION': 48,
'EPT_MISCONFIG': 49,
'WBINVD': 54,
'XSETBV': 55,
'APIC_WRITE': 56,
'INVPCID': 58,
}
SVM_EXIT_REASONS = {
'READ_CR0': 0x000,
'READ_CR3': 0x003,
'READ_CR4': 0x004,
'READ_CR8': 0x008,
'WRITE_CR0': 0x010,
'WRITE_CR3': 0x013,
'WRITE_CR4': 0x014,
'WRITE_CR8': 0x018,
'READ_DR0': 0x020,
'READ_DR1': 0x021,
'READ_DR2': 0x022,
'READ_DR3': 0x023,
'READ_DR4': 0x024,
'READ_DR5': 0x025,
'READ_DR6': 0x026,
'READ_DR7': 0x027,
'WRITE_DR0': 0x030,
'WRITE_DR1': 0x031,
'WRITE_DR2': 0x032,
'WRITE_DR3': 0x033,
'WRITE_DR4': 0x034,
'WRITE_DR5': 0x035,
'WRITE_DR6': 0x036,
'WRITE_DR7': 0x037,
'EXCP_BASE': 0x040,
'INTR': 0x060,
'NMI': 0x061,
'SMI': 0x062,
'INIT': 0x063,
'VINTR': 0x064,
'CR0_SEL_WRITE': 0x065,
'IDTR_READ': 0x066,
'GDTR_READ': 0x067,
'LDTR_READ': 0x068,
'TR_READ': 0x069,
'IDTR_WRITE': 0x06a,
'GDTR_WRITE': 0x06b,
'LDTR_WRITE': 0x06c,
'TR_WRITE': 0x06d,
'RDTSC': 0x06e,
'RDPMC': 0x06f,
'PUSHF': 0x070,
'POPF': 0x071,
'CPUID': 0x072,
'RSM': 0x073,
'IRET': 0x074,
'SWINT': 0x075,
'INVD': 0x076,
'PAUSE': 0x077,
'HLT': 0x078,
'INVLPG': 0x079,
'INVLPGA': 0x07a,
'IOIO': 0x07b,
'MSR': 0x07c,
'TASK_SWITCH': 0x07d,
'FERR_FREEZE': 0x07e,
'SHUTDOWN': 0x07f,
'VMRUN': 0x080,
'VMMCALL': 0x081,
'VMLOAD': 0x082,
'VMSAVE': 0x083,
'STGI': 0x084,
'CLGI': 0x085,
'SKINIT': 0x086,
'RDTSCP': 0x087,
'ICEBP': 0x088,
'WBINVD': 0x089,
'MONITOR': 0x08a,
'MWAIT': 0x08b,
'MWAIT_COND': 0x08c,
'XSETBV': 0x08d,
'NPF': 0x400,
}
# EC definition of HSR (from arch/arm64/include/asm/kvm_arm.h)
AARCH64_EXIT_REASONS = {
'UNKNOWN': 0x00,
'WFI': 0x01,
'CP15_32': 0x03,
'CP15_64': 0x04,
'CP14_MR': 0x05,
'CP14_LS': 0x06,
'FP_ASIMD': 0x07,
'CP10_ID': 0x08,
'CP14_64': 0x0C,
'ILL_ISS': 0x0E,
'SVC32': 0x11,
'HVC32': 0x12,
'SMC32': 0x13,
'SVC64': 0x15,
'HVC64': 0x16,
'SMC64': 0x17,
'SYS64': 0x18,
'IABT': 0x20,
'IABT_HYP': 0x21,
'PC_ALIGN': 0x22,
'DABT': 0x24,
'DABT_HYP': 0x25,
'SP_ALIGN': 0x26,
'FP_EXC32': 0x28,
'FP_EXC64': 0x2C,
'SERROR': 0x2F,
'BREAKPT': 0x30,
'BREAKPT_HYP': 0x31,
'SOFTSTP': 0x32,
'SOFTSTP_HYP': 0x33,
'WATCHPT': 0x34,
'WATCHPT_HYP': 0x35,
'BKPT32': 0x38,
'VECTOR32': 0x3A,
'BRK64': 0x3C,
}
# From include/uapi/linux/kvm.h, KVM_EXIT_xxx
USERSPACE_EXIT_REASONS = {
'UNKNOWN': 0,
'EXCEPTION': 1,
'IO': 2,
'HYPERCALL': 3,
'DEBUG': 4,
'HLT': 5,
'MMIO': 6,
'IRQ_WINDOW_OPEN': 7,
'SHUTDOWN': 8,
'FAIL_ENTRY': 9,
'INTR': 10,
'SET_TPR': 11,
'TPR_ACCESS': 12,
'S390_SIEIC': 13,
'S390_RESET': 14,
'DCR': 15,
'NMI': 16,
'INTERNAL_ERROR': 17,
'OSI': 18,
'PAPR_HCALL': 19,
'S390_UCONTROL': 20,
'WATCHDOG': 21,
'S390_TSCH': 22,
'EPR': 23,
'SYSTEM_EVENT': 24,
}
IOCTL_NUMBERS = {
'SET_FILTER': 0x40082406,
'ENABLE': 0x00002400,
'DISABLE': 0x00002401,
'RESET': 0x00002403,
}
class Arch(object):
"""Class that encapsulates global architecture specific data like
syscall and ioctl numbers.
"""
@staticmethod
def get_arch():
machine = os.uname()[4]
if machine.startswith('ppc'):
return ArchPPC()
elif machine.startswith('aarch64'):
return ArchA64()
elif machine.startswith('s390'):
return ArchS390()
else:
# X86_64
for line in open('/proc/cpuinfo'):
if not line.startswith('flags'):
continue
flags = line.split()
if 'vmx' in flags:
return ArchX86(VMX_EXIT_REASONS)
if 'svm' in flags:
return ArchX86(SVM_EXIT_REASONS)
return
class ArchX86(Arch):
def __init__(self, exit_reasons):
self.sc_perf_evt_open = 298
self.ioctl_numbers = IOCTL_NUMBERS
self.exit_reasons = exit_reasons
class ArchPPC(Arch):
def __init__(self):
self.sc_perf_evt_open = 319
self.ioctl_numbers = IOCTL_NUMBERS
self.ioctl_numbers['ENABLE'] = 0x20002400
self.ioctl_numbers['DISABLE'] = 0x20002401
# PPC comes in 32 and 64 bit and some generated ioctl
# numbers depend on the wordsize.
char_ptr_size = ctypes.sizeof(ctypes.c_char_p)
self.ioctl_numbers['SET_FILTER'] = 0x80002406 | char_ptr_size << 16
class ArchA64(Arch):
def __init__(self):
self.sc_perf_evt_open = 241
self.ioctl_numbers = IOCTL_NUMBERS
self.exit_reasons = AARCH64_EXIT_REASONS
class ArchS390(Arch):
def __init__(self):
self.sc_perf_evt_open = 331
self.ioctl_numbers = IOCTL_NUMBERS
self.exit_reasons = None
ARCH = Arch.get_arch()
def walkdir(path):
"""Returns os.walk() data for specified directory.
As it is only a wrapper it returns the same 3-tuple of (dirpath,
dirnames, filenames).
"""
return next(os.walk(path))
def parse_int_list(list_string):
"""Returns an int list from a string of comma separated integers and
integer ranges."""
integers = []
members = list_string.split(',')
for member in members:
if '-' not in member:
integers.append(int(member))
else:
int_range = member.split('-')
integers.extend(range(int(int_range[0]),
int(int_range[1]) + 1))
return integers
def get_online_cpus():
with open('/sys/devices/system/cpu/online') as cpu_list:
cpu_string = cpu_list.readline()
return parse_int_list(cpu_string)
def get_filters():
filters = {}
filters['kvm_userspace_exit'] = ('reason', USERSPACE_EXIT_REASONS)
if ARCH.exit_reasons:
filters['kvm_exit'] = ('exit_reason', ARCH.exit_reasons)
return filters
libc = ctypes.CDLL('libc.so.6', use_errno=True)
syscall = libc.syscall
class perf_event_attr(ctypes.Structure):
_fields_ = [('type', ctypes.c_uint32),
('size', ctypes.c_uint32),
('config', ctypes.c_uint64),
('sample_freq', ctypes.c_uint64),
('sample_type', ctypes.c_uint64),
('read_format', ctypes.c_uint64),
('flags', ctypes.c_uint64),
('wakeup_events', ctypes.c_uint32),
('bp_type', ctypes.c_uint32),
('bp_addr', ctypes.c_uint64),
('bp_len', ctypes.c_uint64),
]
def __init__(self):
super(self.__class__, self).__init__()
self.type = PERF_TYPE_TRACEPOINT
self.size = ctypes.sizeof(self)
self.read_format = PERF_FORMAT_GROUP
def perf_event_open(attr, pid, cpu, group_fd, flags):
return syscall(ARCH.sc_perf_evt_open, ctypes.pointer(attr),
ctypes.c_int(pid), ctypes.c_int(cpu),
ctypes.c_int(group_fd), ctypes.c_long(flags))
PERF_TYPE_TRACEPOINT = 2
PERF_FORMAT_GROUP = 1 << 3
PATH_DEBUGFS_TRACING = '/sys/kernel/debug/tracing'
PATH_DEBUGFS_KVM = '/sys/kernel/debug/kvm'
class Group(object):
def __init__(self):
self.events = []
def add_event(self, event):
self.events.append(event)
def read(self):
length = 8 * (1 + len(self.events))
read_format = 'xxxxxxxx' + 'Q' * len(self.events)
return dict(zip([event.name for event in self.events],
struct.unpack(read_format,
os.read(self.events[0].fd, length))))
class Event(object):
def __init__(self, name, group, trace_cpu, trace_point, trace_filter,
trace_set='kvm'):
self.name = name
self.fd = None
self.setup_event(group, trace_cpu, trace_point, trace_filter,
trace_set)
def setup_event_attribute(self, trace_set, trace_point):
id_path = os.path.join(PATH_DEBUGFS_TRACING, 'events', trace_set,
trace_point, 'id')
event_attr = perf_event_attr()
event_attr.config = int(open(id_path).read())
return event_attr
def setup_event(self, group, trace_cpu, trace_point, trace_filter,
trace_set):
event_attr = self.setup_event_attribute(trace_set, trace_point)
group_leader = -1
if group.events:
group_leader = group.events[0].fd
fd = perf_event_open(event_attr, -1, trace_cpu,
group_leader, 0)
if fd == -1:
err = ctypes.get_errno()
raise OSError(err, os.strerror(err),
'while calling sys_perf_event_open().')
if trace_filter:
fcntl.ioctl(fd, ARCH.ioctl_numbers['SET_FILTER'],
trace_filter)
self.fd = fd
def enable(self):
fcntl.ioctl(self.fd, ARCH.ioctl_numbers['ENABLE'], 0)
def disable(self):
fcntl.ioctl(self.fd, ARCH.ioctl_numbers['DISABLE'], 0)
def reset(self):
fcntl.ioctl(self.fd, ARCH.ioctl_numbers['RESET'], 0)
class TracepointProvider(object):
def __init__(self):
self.group_leaders = []
self.filters = get_filters()
self._fields = self.get_available_fields()
self.setup_traces()
self.fields = self._fields
def get_available_fields(self):
path = os.path.join(PATH_DEBUGFS_TRACING, 'events', 'kvm')
fields = walkdir(path)[1]
extra = []
for field in fields:
if field in self.filters:
filter_name_, filter_dicts = self.filters[field]
for name in filter_dicts:
extra.append(field + '(' + name + ')')
fields += extra
return fields
def setup_traces(self):
cpus = get_online_cpus()
# The constant is needed as a buffer for python libs, std
# streams and other files that the script opens.
newlim = len(cpus) * len(self._fields) + 50
try:
softlim_, hardlim = resource.getrlimit(resource.RLIMIT_NOFILE)
if hardlim < newlim:
# Now we need CAP_SYS_RESOURCE, to increase the hard limit.
resource.setrlimit(resource.RLIMIT_NOFILE, (newlim, newlim))
else:
# Raising the soft limit is sufficient.
resource.setrlimit(resource.RLIMIT_NOFILE, (newlim, hardlim))
except ValueError:
sys.exit("NOFILE rlimit could not be raised to {0}".format(newlim))
for cpu in cpus:
group = Group()
for name in self._fields:
tracepoint = name
tracefilter = None
match = re.match(r'(.*)\((.*)\)', name)
if match:
tracepoint, sub = match.groups()
tracefilter = ('%s==%d\0' %
(self.filters[tracepoint][0],
self.filters[tracepoint][1][sub]))
group.add_event(Event(name=name,
group=group,
trace_cpu=cpu,
trace_point=tracepoint,
trace_filter=tracefilter))
self.group_leaders.append(group)
def available_fields(self):
return self.get_available_fields()
@property
def fields(self):
return self._fields
@fields.setter
def fields(self, fields):
self._fields = fields
for group in self.group_leaders:
for index, event in enumerate(group.events):
if event.name in fields:
event.reset()
event.enable()
else:
# Do not disable the group leader.
# It would disable all of its events.
if index != 0:
event.disable()
def read(self):
ret = defaultdict(int)
for group in self.group_leaders:
for name, val in group.read().iteritems():
if name in self._fields:
ret[name] += val
return ret
class DebugfsProvider(object):
def __init__(self):
self._fields = self.get_available_fields()
def get_available_fields(self):
return walkdir(PATH_DEBUGFS_KVM)[2]
@property
def fields(self):
return self._fields
@fields.setter
def fields(self, fields):
self._fields = fields
def read(self):
def val(key):
return int(file(PATH_DEBUGFS_KVM + '/' + key).read())
return dict([(key, val(key)) for key in self._fields])
class Stats(object):
def __init__(self, providers, fields=None):
self.providers = providers
self._fields_filter = fields
self.values = {}
self.update_provider_filters()
def update_provider_filters(self):
def wanted(key):
if not self._fields_filter:
return True
return re.match(self._fields_filter, key) is not None
# As we reset the counters when updating the fields we can
# also clear the cache of old values.
self.values = {}
for provider in self.providers:
provider_fields = [key for key in provider.get_available_fields()
if wanted(key)]
provider.fields = provider_fields
@property
def fields_filter(self):
return self._fields_filter
@fields_filter.setter
def fields_filter(self, fields_filter):
self._fields_filter = fields_filter
self.update_provider_filters()
def get(self):
for provider in self.providers:
new = provider.read()
for key in provider.fields:
oldval = self.values.get(key, (0, 0))
newval = new.get(key, 0)
newdelta = None
if oldval is not None:
newdelta = newval - oldval[0]
self.values[key] = (newval, newdelta)
return self.values
LABEL_WIDTH = 40
NUMBER_WIDTH = 10
class Tui(object):
def __init__(self, stats):
self.stats = stats
self.screen = None
self.drilldown = False
self.update_drilldown()
def __enter__(self):
"""Initialises curses for later use. Based on curses.wrapper
implementation from the Python standard library."""
self.screen = curses.initscr()
curses.noecho()
curses.cbreak()
# The try/catch works around a minor bit of
# over-conscientiousness in the curses module, the error
# return from C start_color() is ignorable.
try:
curses.start_color()
except:
pass
curses.use_default_colors()
return self
def __exit__(self, *exception):
"""Resets the terminal to its normal state. Based on curses.wrappre
implementation from the Python standard library."""
if self.screen:
self.screen.keypad(0)
curses.echo()
curses.nocbreak()
curses.endwin()
def update_drilldown(self):
if not self.stats.fields_filter:
self.stats.fields_filter = r'^[^\(]*$'
elif self.stats.fields_filter == r'^[^\(]*$':
self.stats.fields_filter = None
def refresh(self, sleeptime):
self.screen.erase()
self.screen.addstr(0, 0, 'kvm statistics - summary', curses.A_BOLD)
self.screen.addstr(2, 1, 'Event')
self.screen.addstr(2, 1 + LABEL_WIDTH + NUMBER_WIDTH -
len('Total'), 'Total')
self.screen.addstr(2, 1 + LABEL_WIDTH + NUMBER_WIDTH + 8 -
len('Current'), 'Current')
row = 3
stats = self.stats.get()
def sortkey(x):
if stats[x][1]:
return (-stats[x][1], -stats[x][0])
else:
return (0, -stats[x][0])
for key in sorted(stats.keys(), key=sortkey):
if row >= self.screen.getmaxyx()[0]:
break
values = stats[key]
if not values[0] and not values[1]:
break
col = 1
self.screen.addstr(row, col, key)
col += LABEL_WIDTH
self.screen.addstr(row, col, '%10d' % (values[0],))
col += NUMBER_WIDTH
if values[1] is not None:
self.screen.addstr(row, col, '%8d' % (values[1] / sleeptime,))
row += 1
self.screen.refresh()
def show_filter_selection(self):
while True:
self.screen.erase()
self.screen.addstr(0, 0,
"Show statistics for events matching a regex.",
curses.A_BOLD)
self.screen.addstr(2, 0,
"Current regex: {0}"
.format(self.stats.fields_filter))
self.screen.addstr(3, 0, "New regex: ")
curses.echo()
regex = self.screen.getstr()
curses.noecho()
if len(regex) == 0:
return
try:
re.compile(regex)
self.stats.fields_filter = regex
return
except re.error:
continue
def show_stats(self):
sleeptime = 0.25
while True:
self.refresh(sleeptime)
curses.halfdelay(int(sleeptime * 10))
sleeptime = 3
try:
char = self.screen.getkey()
if char == 'x':
self.drilldown = not self.drilldown
self.update_drilldown()
if char == 'q':
break
if char == 'f':
self.show_filter_selection()
except KeyboardInterrupt:
break
except curses.error:
continue
def batch(stats):
s = stats.get()
time.sleep(1)
s = stats.get()
for key in sorted(s.keys()):
values = s[key]
print '%-42s%10d%10d' % (key, values[0], values[1])
def log(stats):
keys = sorted(stats.get().iterkeys())
def banner():
for k in keys:
print '%s' % k,
print
def statline():
s = stats.get()
for k in keys:
print ' %9d' % s[k][1],
print
line = 0
banner_repeat = 20
while True:
time.sleep(1)
if line % banner_repeat == 0:
banner()
statline()
line += 1
def get_options():
description_text = """
This script displays various statistics about VMs running under KVM.
The statistics are gathered from the KVM debugfs entries and / or the
currently available perf traces.
The monitoring takes additional cpu cycles and might affect the VM's
performance.
Requirements:
- Access to:
/sys/kernel/debug/kvm
/sys/kernel/debug/trace/events/*
/proc/pid/task
- /proc/sys/kernel/perf_event_paranoid < 1 if user has no
CAP_SYS_ADMIN and perf events are used.
- CAP_SYS_RESOURCE if the hard limit is not high enough to allow
the large number of files that are possibly opened.
"""
class PlainHelpFormatter(optparse.IndentedHelpFormatter):
def format_description(self, description):
if description:
return description + "\n"
else:
return ""
optparser = optparse.OptionParser(description=description_text,
formatter=PlainHelpFormatter())
optparser.add_option('-1', '--once', '--batch',
action='store_true',
default=False,
dest='once',
help='run in batch mode for one second',
)
optparser.add_option('-l', '--log',
action='store_true',
default=False,
dest='log',
help='run in logging mode (like vmstat)',
)
optparser.add_option('-t', '--tracepoints',
action='store_true',
default=False,
dest='tracepoints',
help='retrieve statistics from tracepoints',
)
optparser.add_option('-d', '--debugfs',
action='store_true',
default=False,
dest='debugfs',
help='retrieve statistics from debugfs',
)
optparser.add_option('-f', '--fields',
action='store',
default=None,
dest='fields',
help='fields to display (regex)',
)
(options, _) = optparser.parse_args(sys.argv)
return options
def get_providers(options):
providers = []
if options.tracepoints:
providers.append(TracepointProvider())
if options.debugfs:
providers.append(DebugfsProvider())
if len(providers) == 0:
providers.append(TracepointProvider())
return providers
def check_access(options):
if not os.path.exists('/sys/kernel/debug'):
sys.stderr.write('Please enable CONFIG_DEBUG_FS in your kernel.')
sys.exit(1)
if not os.path.exists(PATH_DEBUGFS_KVM):
sys.stderr.write("Please make sure, that debugfs is mounted and "
"readable by the current user:\n"
"('mount -t debugfs debugfs /sys/kernel/debug')\n"
"Also ensure, that the kvm modules are loaded.\n")
sys.exit(1)
if not os.path.exists(PATH_DEBUGFS_TRACING) and (options.tracepoints
or not options.debugfs):
sys.stderr.write("Please enable CONFIG_TRACING in your kernel "
"when using the option -t (default).\n"
"If it is enabled, make {0} readable by the "
"current user.\n"
.format(PATH_DEBUGFS_TRACING))
if options.tracepoints:
sys.exit(1)
sys.stderr.write("Falling back to debugfs statistics!\n")
options.debugfs = True
sleep(5)
return options
def main():
options = get_options()
options = check_access(options)
providers = get_providers(options)
stats = Stats(providers, fields=options.fields)
if options.log:
log(stats)
elif not options.once:
with Tui(stats) as tui:
tui.show_stats()
else:
batch(stats)
if __name__ == "__main__":
main()