Having stats for single VMs can help to determine the problem of a VM
without the need of running other tools like perf.
The tracepoints already allowed pid level monitoring, but kvm_stat
didn't have support for it till now. Support for the newly implemented
debugfs vm monitoring was also implemented.
Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxxxxxxx>
---
tools/kvm/kvm_stat | 183 +++++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 163 insertions(+), 20 deletions(-)
diff --git a/tools/kvm/kvm_stat b/tools/kvm/kvm_stat
index 769d884..a4643f5 100755
--- a/tools/kvm/kvm_stat
+++ b/tools/kvm/kvm_stat
@@ -365,12 +365,16 @@ class Group(object):
os.read(self.events[0].fd, length))))
class Event(object):
- def __init__(self, name, group, trace_cpu, trace_point, trace_filter,
- trace_set='kvm'):
+ def __init__(self, name, group, trace_cpu, trace_pid, 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)
+ self.setup_event(group, trace_cpu, trace_pid, trace_point,
+ trace_filter, trace_set)
+
+ def __del__(self):
+ if self.fd:
+ os.close(self.fd)
def setup_event_attribute(self, trace_set, trace_point):
id_path = os.path.join(PATH_DEBUGFS_TRACING, 'events', trace_set,
@@ -380,16 +384,16 @@ class Event(object):
event_attr.config = int(open(id_path).read())
return event_attr
- def setup_event(self, group, trace_cpu, trace_point, trace_filter,
- trace_set):
+ def setup_event(self, group, trace_cpu, trace_pid, 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)
+ fd = 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),
@@ -415,8 +419,7 @@ class TracepointProvider(object):
self.group_leaders = []
self.filters = get_filters()
self._fields = self.get_available_fields()
- self.setup_traces()
- self.fields = self._fields
+ self._pid = 0
def get_available_fields(self):
path = os.path.join(PATH_DEBUGFS_TRACING, 'events', 'kvm')
@@ -431,11 +434,17 @@ class TracepointProvider(object):
return fields
def setup_traces(self):
- cpus = get_online_cpus()
+ if self._pid > 0:
+ # 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]
+ else:
+ groupids = 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
+ newlim = len(groupids) * len(self._fields) + 50
try:
softlim_, hardlim = resource.getrlimit(resource.RLIMIT_NOFILE)
@@ -449,7 +458,7 @@ class TracepointProvider(object):
except ValueError:
sys.exit("NOFILE rlimit could not be raised to {0}".format(newlim))
- for cpu in cpus:
+ for groupid in groupids:
group = Group()
for name in self._fields:
tracepoint = name
@@ -461,11 +470,22 @@ class TracepointProvider(object):
(self.filters[tracepoint][0],
self.filters[tracepoint][1][sub]))
+ # From perf_event_open(2):
+ # pid > 0 and cpu == -1
+ # This measures the specified process/thread on any CPU.
+ #
+ # pid == -1 and cpu >= 0
+ # This measures all processes/threads on the specified CPU.
+ trace_cpu = groupid if self._pid == 0 else -1
+ trace_pid = int(groupid) if self._pid != 0 else -1
+
group.add_event(Event(name=name,
group=group,
- trace_cpu=cpu,
+ trace_cpu=trace_cpu,
+ trace_pid=trace_pid,
trace_point=tracepoint,
trace_filter=tracefilter))
+
self.group_leaders.append(group)
def available_fields(self):
@@ -489,6 +509,17 @@ class TracepointProvider(object):
if index != 0:
event.disable()
+ @property
+ def pid(self):
+ return self._pid
+
+ @pid.setter
+ def pid(self, pid):
+ self._pid = pid
+ self.group_leaders = []
+ self.setup_traces()
+ self.fields = self._fields
+
def read(self):
ret = defaultdict(int)
for group in self.group_leaders:
@@ -500,6 +531,8 @@ class TracepointProvider(object):
class DebugfsProvider(object):
def __init__(self):
self._fields = self.get_available_fields()
+ self._pid = 0
+ self.do_read = True
def get_available_fields(self):
return walkdir(PATH_DEBUGFS_KVM)[2]
@@ -512,16 +545,57 @@ class DebugfsProvider(object):
def fields(self, fields):
self._fields = fields
+ @property
+ def pid(self):
+ return self._pid
+
+ @pid.setter
+ def pid(self, pid):
+ if pid != 0:
+ self._pid = pid
+
+ vms = walkdir(PATH_DEBUGFS_KVM)[1]
+ if len(vms) == 0:
+ self.do_read = False
+
+ self.paths = filter(lambda x: "{}-".format(pid) in x, vms)
+
+ else:
+ self.paths = ['']
+ self.do_read = True
+
def read(self):
- def val(key):
- return int(file(PATH_DEBUGFS_KVM + '/' + key).read())
- return dict([(key, val(key)) for key in self._fields])
+ """Returns a dict with format:'file name / field -> current value'."""
+ results = {}
+
+ # If no debugfs filtering support is available, then don't read.
+ if not self.do_read:
+ return results
+
+ for path in self.paths:
+ for field in self._fields:
+ results[field] = results.get(field, 0) \
+ + self.read_field(field, path)
+
+ return results
+
+ def read_field(self, field, path):
+ """Returns the value of a single field from a specific VM."""
+ try:
+ return int(open(os.path.join(PATH_DEBUGFS_KVM,
+ path,
+ field))
+ .read())
+ except IOError:
+ return 0
class Stats(object):
- def __init__(self, providers, fields=None):
+ def __init__(self, providers, pid, fields=None):
self.providers = providers
+ self._pid_filter = pid
self._fields_filter = fields
self.values = {}
+ self.update_provider_pid()
self.update_provider_filters()
def update_provider_filters(self):
@@ -538,6 +612,10 @@ class Stats(object):
if wanted(key)]
provider.fields = provider_fields
+ def update_provider_pid(self):
+ for provider in self.providers:
+ provider.pid = self._pid_filter
+
@property
def fields_filter(self):
return self._fields_filter
@@ -547,6 +625,16 @@ class Stats(object):
self._fields_filter = fields_filter
self.update_provider_filters()
+ @property
+ def pid_filter(self):
+ return self._pid_filter
+
+ @pid_filter.setter
+ def pid_filter(self, pid):
+ self._pid_filter = pid
+ self.values = {}
+ self.update_provider_pid()
+
def get(self):
for provider in self.providers:
new = provider.read()
@@ -603,9 +691,17 @@ class Tui(object):
elif self.stats.fields_filter == r'^[^\(]*$':
self.stats.fields_filter = None
+ def update_pid(self, pid):
+ self.stats.pid_filter = pid
+
def refresh(self, sleeptime):
self.screen.erase()
- self.screen.addstr(0, 0, 'kvm statistics - summary', curses.A_BOLD)
+ if self.stats.pid_filter > 0:
+ self.screen.addstr(0, 0, 'kvm statistics - pid {0}'
+ .format(self.stats.pid_filter),
+ curses.A_BOLD)
+ else:
+ 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')
@@ -657,6 +753,37 @@ class Tui(object):
except re.error:
continue
+ def show_vm_selection(self):
+ while True:
+ self.screen.erase()
+ self.screen.addstr(0, 0,
+ 'Show statistics for specific pid.',
+ curses.A_BOLD)
+ self.screen.addstr(1, 0,
+ 'This might limit the shown data to the trace '
+ 'statistics.')
+
+ curses.echo()
+ self.screen.addstr(3, 0, "Pid [0 or pid]: ")
+ pid = self.screen.getstr()
+ curses.noecho()
+
+ try:
+ pid = int(pid)
+
+ if pid == 0:
+ self.update_pid(pid)
+ break
+ else:
+ if not os.path.isdir(os.path.join('/proc/', str(pid))):
+ continue
+ else:
+ self.update_pid(pid)
+ break
+
+ except ValueError:
+ continue
+
def show_stats(self):
sleeptime = 0.25
while True:
@@ -672,6 +799,8 @@ class Tui(object):
break
if char == 'f':
self.show_filter_selection()
+ if char == 'p':
+ self.show_vm_selection()
except KeyboardInterrupt:
break
except curses.error:
@@ -764,6 +893,13 @@ Requirements:
dest='fields',
help='fields to display (regex)',
)
+ optparser.add_option('-p', '--pid',
+ action='store',
+ default=0,
+ type=int,
+ dest='pid',
+ help='restrict statistics to pid',
+ )
(options, _) = optparser.parse_args(sys.argv)
return options
@@ -810,8 +946,15 @@ def check_access(options):
def main():
options = get_options()
options = check_access(options)
+
+ if (options.pid > 0 and
+ not os.path.isdir(os.path.join('/proc/',
+ str(options.pid)))):
+ sys.stderr.write('Did you use a (unsupported) tid instead of a pid?\n')
+ sys.exit('Specified pid does not exist.')
+
providers = get_providers(options)
- stats = Stats(providers, fields=options.fields)
+ stats = Stats(providers, options.pid, fields=options.fields)
if options.log:
log(stats)
--
2.3.0
--
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