From c469117df05955901d2950b6130770e526b1dbf4 Mon Sep 17 00:00:00 2001 From: Stefan Raspl Date: Wed, 7 Jun 2017 21:08:32 +0200 Subject: [PATCH] tools/kvm_stat: simplify initializers Simplify a couple of initialization routines: * TracepointProvider and DebugfsProvider: Pass pid into __init__() instead of switching to the requested value in an extra call after initializing to the default first. * Pass a single options object into Stats.__init__(), delaying options evaluation accordingly, instead of evaluating options first and passing several parts of the options object to Stats.__init__() individually. * Eliminate Stats.update_provider_pid(), since this 2-line function is now used in a single place only. * Remove extra call to update_drilldown() in Tui.__init__() by getting the value of options.fields right initially when parsing options. * Simplify get_providers() logic. * Avoid duplicate fields initialization by handling it once in the providers' __init__() methods. Signed-off-by: Stefan Raspl Signed-off-by: Paolo Bonzini --- tools/kvm/kvm_stat/kvm_stat | 74 ++++++++++++++++++------------------- 1 file changed, 36 insertions(+), 38 deletions(-) diff --git a/tools/kvm/kvm_stat/kvm_stat b/tools/kvm/kvm_stat/kvm_stat index e38791ddb37a..b8522d2ddb0a 100755 --- a/tools/kvm/kvm_stat/kvm_stat +++ b/tools/kvm/kvm_stat/kvm_stat @@ -295,6 +295,13 @@ 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. @@ -581,11 +588,11 @@ class TracepointProvider(object): Manages the events/groups from which it acquires its data. """ - def __init__(self): + def __init__(self, pid, fields_filter): self.group_leaders = [] self.filters = get_filters() - self._fields = self.get_available_fields() - self._pid = 0 + self.update_fields(fields_filter) + self.pid = pid def get_available_fields(self): """Returns a list of available event's of format 'event name(filter @@ -613,6 +620,11 @@ class TracepointProvider(object): fields += extra return fields + 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)] + def setup_traces(self): """Creates all event and group objects needed to be able to retrieve data.""" @@ -723,13 +735,12 @@ class TracepointProvider(object): class DebugfsProvider(object): """Provides data from the files that KVM creates in the kvm debugfs folder.""" - def __init__(self): - self._fields = self.get_available_fields() + def __init__(self, pid, fields_filter): + self.update_fields(fields_filter) self._baseline = {} - self._pid = 0 self.do_read = True self.paths = [] - self.reset() + self.pid = pid def get_available_fields(self): """"Returns a list of available fields. @@ -739,6 +750,11 @@ class DebugfsProvider(object): """ return 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)] + @property def fields(self): return self._fields @@ -754,9 +770,8 @@ class DebugfsProvider(object): @pid.setter def pid(self, pid): + self._pid = pid if pid != 0: - self._pid = pid - vms = walkdir(PATH_DEBUGFS_KVM)[1] if len(vms) == 0: self.do_read = False @@ -818,33 +833,19 @@ class Stats(object): provider data. """ - def __init__(self, providers, pid, fields=None): - self.providers = providers - self._pid_filter = pid - self._fields_filter = fields + def __init__(self, options): + self.providers = get_providers(options) + self._pid_filter = options.pid + self._fields_filter = options.fields self.values = {} - self.update_provider_pid() - self.update_provider_filters() def update_provider_filters(self): """Propagates fields filters to providers.""" - 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 - - def update_provider_pid(self): - """Propagates pid filters to providers.""" - for provider in self.providers: - provider.pid = self._pid_filter + provider.update_fields(self._fields_filter) def reset(self): self.values = {} @@ -870,7 +871,8 @@ class Stats(object): if pid != self._pid_filter: self._pid_filter = pid self.values = {} - self.update_provider_pid() + for provider in self.providers: + provider.pid = self._pid_filter def get(self): """Returns a dict with field -> (value, delta to last value) of all @@ -896,7 +898,6 @@ class Tui(object): def __init__(self, stats): self.stats = stats self.screen = None - self.update_drilldown() def __enter__(self): """Initialises curses for later use. Based on curses.wrapper @@ -1270,7 +1271,7 @@ Press any other key to refresh statistics immediately. ) optparser.add_option('-f', '--fields', action='store', - default=None, + default=DEFAULT_REGEX, dest='fields', help='fields to display (regex)', ) @@ -1297,12 +1298,10 @@ def get_providers(options): """Returns a list of data providers depending on the passed options.""" providers = [] - if options.tracepoints: - providers.append(TracepointProvider()) if options.debugfs: - providers.append(DebugfsProvider()) - if len(providers) == 0: - providers.append(TracepointProvider()) + providers.append(DebugfsProvider(options.pid, options.fields)) + if options.tracepoints or not providers: + providers.append(TracepointProvider(options.pid, options.fields)) return providers @@ -1347,8 +1346,7 @@ def main(): 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, options.pid, fields=options.fields) + stats = Stats(options) if options.log: log(stats) -- 2.30.2