Quite a few of the functions are used only in a single class. Moving
functions accordingly to improve the overall structure.
Furthermore, introduce a base class for the providers, which might also
come handy for future extensions.
Signed-off-by: Stefan Raspl <raspl@xxxxxxxxxxxxxxxxxx>
---
tools/kvm/kvm_stat/kvm_stat | 327 ++++++++++++++++++++++----------------------
1 file changed, 165 insertions(+), 162 deletions(-)
diff --git a/tools/kvm/kvm_stat/kvm_stat b/tools/kvm/kvm_stat/kvm_stat
index b8522d2ddb0a..f81ed208307f 100755
--- a/tools/kvm/kvm_stat/kvm_stat
+++ b/tools/kvm/kvm_stat/kvm_stat
@@ -295,121 +295,6 @@ class ArchS390(Arch):
ARCH = Arch.get_arch()
-def is_field_wanted(fields_filter, field):
- """Indicate whether field is valid according to fields_filter."""
- if not fields_filter:
- return True
- return re.match(fields_filter, field) is not None
-
-
-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_pid_from_gname(gname):
- """Fuzzy function to convert guest name to QEMU process pid.
-
- Returns a list of potential pids, can be empty if no match found.
- Throws an exception on processing errors.
-
- """
- pids = []
- try:
- child = subprocess.Popen(['ps', '-A', '--format', 'pid,args'],
- stdout=subprocess.PIPE)
- except:
- raise Exception
- for line in child.stdout:
- line = line.lstrip().split(' ', 1)
- # perform a sanity check before calling the more expensive
- # function to possibly extract the guest name
- if ' -name ' in line[1] and gname == get_gname_from_pid(line[0]):
- pids.append(int(line[0]))
- child.stdout.close()
-
- return pids
-
-
-def get_gname_from_pid(pid):
- """Returns the guest name for a QEMU process pid.
-
- Extracts the guest name from the QEMU comma line by processing the '-name'
- option. Will also handle names specified out of sequence.
-
- """
- name = ''
- try:
- line = open('/proc/{}/cmdline'.format(pid), 'rb').read().split('\0')
- parms = line[line.index('-name') + 1].split(',')
- while '' in parms:
- # commas are escaped (i.e. ',,'), hence e.g. 'foo,bar' results in
- # ['foo', '', 'bar'], which we revert here
- idx = parms.index('')
- parms[idx - 1] += ',' + parms[idx + 1]
- del parms[idx:idx+2]
- # the '-name' switch allows for two ways to specify the guest name,
- # where the plain name overrides the name specified via 'guest='
- for arg in parms:
- if '=' not in arg:
- name = arg
- break
- if arg[:6] == 'guest=':
- name = arg[6:]
- except (ValueError, IOError, IndexError):
- pass
-
- return name
-
-
-def get_online_cpus():
- """Returns a list of cpu id integers."""
- with open('/sys/devices/system/cpu/online') as cpu_list:
- cpu_string = cpu_list.readline()
- return parse_int_list(cpu_string)
-
-
-def get_filters():
- """Returns a dict of trace events, their filter ids and
- the values that can be filtered.
-
- Trace events can be filtered for special values by setting a
- filter string via an ioctl. The string normally has the format
- identifier==value. For each filter a new event will be created, to
- be able to distinguish the events.
-
- """
- 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):
"""Struct that holds the necessary data to set up a trace event.
@@ -439,25 +324,6 @@ class perf_event_attr(ctypes.Structure):
self.read_format = PERF_FORMAT_GROUP
-def perf_event_open(attr, pid, cpu, group_fd, flags):
- """Wrapper for the sys_perf_evt_open() syscall.
-
- Used to set up performance events, returns a file descriptor or -1
- on error.
-
- Attributes are:
- - syscall number
- - struct perf_event_attr *
- - pid or -1 to monitor all pids
- - cpu number or -1 to monitor all cpus
- - The file descriptor of the group leader or -1 to create a group.
- - 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
@@ -502,6 +368,8 @@ class Event(object):
"""Represents a performance event and manages its life cycle."""
def __init__(self, name, group, trace_cpu, trace_pid, trace_point,
trace_filter, trace_set='kvm'):
+ self.libc = ctypes.CDLL('libc.so.6', use_errno=True)
+ self.syscall = self.libc.syscall
self.name = name
self.fd = None
self.setup_event(group, trace_cpu, trace_pid, trace_point,
@@ -518,6 +386,25 @@ class Event(object):
if self.fd:
os.close(self.fd)
+ def perf_event_open(self, attr, pid, cpu, group_fd, flags):
+ """Wrapper for the sys_perf_evt_open() syscall.
+
+ Used to set up performance events, returns a file descriptor or -1
+ on error.
+
+ Attributes are:
+ - syscall number
+ - struct perf_event_attr *
+ - pid or -1 to monitor all pids
+ - cpu number or -1 to monitor all cpus
+ - The file descriptor of the group leader or -1 to create a group.
+ - flags
+
+ """
+ return self.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))
+
def setup_event_attribute(self, trace_set, trace_point):
"""Returns an initialized ctype perf_event_attr struct."""
@@ -546,8 +433,8 @@ class Event(object):
if group.events:
group_leader = group.events[0].fd
- fd = perf_event_open(event_attr, trace_pid,
- trace_cpu, group_leader, 0)
+ fd = self.perf_event_open(event_attr, trace_pid,
+ trace_cpu, group_leader, 0)
if fd == -1:
err = ctypes.get_errno()
raise OSError(err, os.strerror(err),
@@ -582,7 +469,26 @@ class Event(object):
fcntl.ioctl(self.fd, ARCH.ioctl_numbers['RESET'], 0)
-class TracepointProvider(object):
+class Provider(object):
+ """Encapsulates functionalities used by all providers."""
+ @staticmethod
+ def is_field_wanted(fields_filter, field):
+ """Indicate whether field is valid according to fields_filter."""
+ if not fields_filter:
+ return True
+ return re.match(fields_filter, field) is not None
+
+ @staticmethod
+ 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))
+
+
+class TracepointProvider(Provider):
"""Data provider for the stats class.
Manages the events/groups from which it acquires its data.
@@ -590,10 +496,27 @@ class TracepointProvider(object):
"""
def __init__(self, pid, fields_filter):
self.group_leaders = []
- self.filters = get_filters()
+ self.filters = self.get_filters()
self.update_fields(fields_filter)
self.pid = pid
+ @staticmethod
+ def get_filters():
+ """Returns a dict of trace events, their filter ids and
+ the values that can be filtered.
+
+ Trace events can be filtered for special values by setting a
+ filter string via an ioctl. The string normally has the format
+ identifier==value. For each filter a new event will be created, to
+ be able to distinguish the events.
+
+ """
+ filters = {}
+ filters['kvm_userspace_exit'] = ('reason', USERSPACE_EXIT_REASONS)
+ if ARCH.exit_reasons:
+ filters['kvm_exit'] = ('exit_reason', ARCH.exit_reasons)
+ return filters
+
def get_available_fields(self):
"""Returns a list of available event's of format 'event name(filter
name)'.
@@ -610,7 +533,7 @@ class TracepointProvider(object):
"""
path = os.path.join(PATH_DEBUGFS_TRACING, 'events', 'kvm')
- fields = walkdir(path)[1]
+ fields = self.walkdir(path)[1]
extra = []
for field in fields:
if field in self.filters:
@@ -623,7 +546,30 @@ class TracepointProvider(object):
def update_fields(self, fields_filter):
"""Refresh fields, applying fields_filter"""
self._fields = [field for field in self.get_available_fields()
- if is_field_wanted(fields_filter, field)]
+ if self.is_field_wanted(fields_filter, field)]
+
+ @staticmethod
+ def get_online_cpus():
+ """Returns a list of cpu id integers."""
+ 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
+
+ with open('/sys/devices/system/cpu/online') as cpu_list:
+ cpu_string = cpu_list.readline()
+ return parse_int_list(cpu_string)
def setup_traces(self):
"""Creates all event and group objects needed to be able to retrieve
@@ -633,9 +579,9 @@ class TracepointProvider(object):
# Fetch list of all threads of the monitored pid, as qemu
# starts a thread for each vcpu.
path = os.path.join('/proc', str(self._pid), 'task')
- groupids = walkdir(path)[1]
+ groupids = self.walkdir(path)[1]
else:
- groupids = get_online_cpus()
+ groupids = self.get_online_cpus()
# The constant is needed as a buffer for python libs, std
# streams and other files that the script opens.
@@ -732,7 +678,7 @@ class TracepointProvider(object):
event.reset()
-class DebugfsProvider(object):
+class DebugfsProvider(Provider):
"""Provides data from the files that KVM creates in the kvm debugfs
folder."""
def __init__(self, pid, fields_filter):
@@ -748,12 +694,12 @@ class DebugfsProvider(object):
The fields are all available KVM debugfs files
"""
- return walkdir(PATH_DEBUGFS_KVM)[2]
+ return self.walkdir(PATH_DEBUGFS_KVM)[2]
def update_fields(self, fields_filter):
"""Refresh fields, applying fields_filter"""
self._fields = [field for field in self.get_available_fields()
- if is_field_wanted(fields_filter, field)]
+ if self.is_field_wanted(fields_filter, field)]
@property
def fields(self):
@@ -772,7 +718,7 @@ class DebugfsProvider(object):
def pid(self, pid):
self._pid = pid
if pid != 0:
- vms = walkdir(PATH_DEBUGFS_KVM)[1]
+ vms = self.walkdir(PATH_DEBUGFS_KVM)[1]
if len(vms) == 0:
self.do_read = False
@@ -834,11 +780,23 @@ class Stats(object):
"""
def __init__(self, options):
- self.providers = get_providers(options)
+ self.providers = self.get_providers(options)
self._pid_filter = options.pid
self._fields_filter = options.fields
self.values = {}
+ @staticmethod
+ def get_providers(options):
+ """Returns a list of data providers depending on the passed options."""
+ providers = []
+
+ if options.debugfs:
+ providers.append(DebugfsProvider(options.pid, options.fields))
+ if options.tracepoints or not providers:
+ providers.append(TracepointProvider(options.pid, options.fields))
+
+ return providers
+
def update_provider_filters(self):
"""Propagates fields filters to providers."""
# As we reset the counters when updating the fields we can
@@ -933,6 +891,63 @@ class Tui(object):
curses.nocbreak()
curses.endwin()
+ @staticmethod
+ def get_pid_from_gname(gname):
+ """Fuzzy function to convert guest name to QEMU process pid.
+
+ Returns a list of potential pids, can be empty if no match found.
+ Throws an exception on processing errors.
+
+ """
+ pids = []
+ try:
+ child = subprocess.Popen(['ps', '-A', '--format', 'pid,args'],
+ stdout=subprocess.PIPE)
+ except:
+ raise Exception
+ for line in child.stdout:
+ line = line.lstrip().split(' ', 1)
+ # perform a sanity check before calling the more expensive
+ # function to possibly extract the guest name
+ if (' -name ' in line[1] and
+ gname == self.get_gname_from_pid(line[0])):
+ pids.append(int(line[0]))
+ child.stdout.close()
+
+ return pids
+
+ @staticmethod
+ def get_gname_from_pid(pid):
+ """Returns the guest name for a QEMU process pid.
+
+ Extracts the guest name from the QEMU comma line by processing the
+ '-name' option. Will also handle names specified out of sequence.
+
+ """
+ name = ''
+ try:
+ line = open('/proc/{}/cmdline'
+ .format(pid), 'rb').read().split('\0')
+ parms = line[line.index('-name') + 1].split(',')
+ while '' in parms:
+ # commas are escaped (i.e. ',,'), hence e.g. 'foo,bar' results
+ # in # ['foo', '', 'bar'], which we revert here
+ idx = parms.index('')
+ parms[idx - 1] += ',' + parms[idx + 1]
+ del parms[idx:idx+2]
+ # the '-name' switch allows for two ways to specify the guest name,
+ # where the plain name overrides the name specified via 'guest='
+ for arg in parms:
+ if '=' not in arg:
+ name = arg
+ break
+ if arg[:6] == 'guest=':
+ name = arg[6:]
+ except (ValueError, IOError, IndexError):
+ pass
+
+ return name
+
def update_drilldown(self):
"""Sets or removes a filter that only allows fields without braces."""
if not self.stats.fields_filter:
@@ -950,7 +965,7 @@ class Tui(object):
if pid is None:
pid = self.stats.pid_filter
self.screen.erase()
- gname = get_gname_from_pid(pid)
+ gname = self.get_gname_from_pid(pid)
if gname:
gname = ('({})'.format(gname[:MAX_GUEST_NAME_LEN] + '...'
if len(gname) > MAX_GUEST_NAME_LEN
@@ -1096,7 +1111,7 @@ class Tui(object):
else:
pids = []
try:
- pids = get_pid_from_gname(gname)
+ pids = self.get_pid_from_gname(gname)
except:
msg = '"' + gname + '": Internal error while searching, ' \
'use pid filter instead'
@@ -1229,7 +1244,7 @@ Press any other key to refresh statistics immediately.
def cb_guest_to_pid(option, opt, val, parser):
try:
- pids = get_pid_from_gname(val)
+ pids = Tui.get_pid_from_gname(val)
except:
raise optparse.OptionValueError('Error while searching for guest '
'"{}", use "-p" to specify a pid '
@@ -1294,18 +1309,6 @@ Press any other key to refresh statistics immediately.
return options
-def get_providers(options):
- """Returns a list of data providers depending on the passed options."""
- providers = []
-
- if options.debugfs:
- providers.append(DebugfsProvider(options.pid, options.fields))
- if options.tracepoints or not providers:
- providers.append(TracepointProvider(options.pid, options.fields))
-
- return providers
-
-
def check_access(options):
"""Exits if the current user can't access all needed directories."""
if not os.path.exists('/sys/kernel/debug'):
--
2.11.2
