From 639ce1831082084af80290c79f06a5794a3caa0b Mon Sep 17 00:00:00 2001 From: Janosch Frank Date: Mon, 11 Jan 2016 16:17:39 +0100 Subject: [PATCH] scripts/kvm/kvm_stat: Introduce main function The main function should be the main location for initialization and helps encapsulating variables into a scope. This way they don't have to be global and might be mistaken for local ones. As the providers variable is scoped now it can't be accessed from within the Stats class. Hence, the global access to the variable was changed to a local one. Reviewed-by: Jason J. Herne Signed-off-by: Janosch Frank Message-Id: <1452525484-32309-10-git-send-email-frankja@linux.vnet.ibm.com> Signed-off-by: Paolo Bonzini --- scripts/kvm/kvm_stat | 145 +++++++++++++++++++++++-------------------- 1 file changed, 78 insertions(+), 67 deletions(-) diff --git a/scripts/kvm/kvm_stat b/scripts/kvm/kvm_stat index 6f0692d60a..9f943ef202 100755 --- a/scripts/kvm/kvm_stat +++ b/scripts/kvm/kvm_stat @@ -285,8 +285,6 @@ def detect_platform(): s390_init() return -detect_platform() - def walkdir(path): """Returns os.walk() data for specified directory. @@ -453,7 +451,7 @@ class Stats: return True return re.match(self.fields_filter, key) is not None self.values = dict() - for d in providers: + for d in self.providers: provider_fields = [key for key in d.fields() if wanted(key)] for key in provider_fields: self.values[key] = None @@ -462,7 +460,7 @@ class Stats: self.fields_filter = fields_filter self._update() def get(self): - for d in providers: + for d in self.providers: new = d.read() for key in d.fields(): oldval = self.values.get(key, (0, 0)) @@ -473,20 +471,6 @@ class Stats: self.values[key] = (newval, newdelta) return self.values -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): - sys.stderr.write("Please make {0} readable by the current user.\n" - .format(PATH_DEBUGFS_TRACING)) - sys.exit(1) - LABEL_WIDTH = 40 NUMBER_WIDTH = 10 @@ -576,56 +560,83 @@ def log(stats): statline() line += 1 -options = optparse.OptionParser() -options.add_option('-1', '--once', '--batch', - action = 'store_true', - default = False, - dest = 'once', - help = 'run in batch mode for one second', - ) -options.add_option('-l', '--log', - action = 'store_true', - default = False, - dest = 'log', - help = 'run in logging mode (like vmstat)', - ) -options.add_option('-t', '--tracepoints', - action = 'store_true', - default = False, - dest = 'tracepoints', - help = 'retrieve statistics from tracepoints', - ) -options.add_option('-d', '--debugfs', - action = 'store_true', - default = False, - dest = 'debugfs', - help = 'retrieve statistics from debugfs', - ) -options.add_option('-f', '--fields', - action = 'store', - default = None, - dest = 'fields', - help = 'fields to display (regex)', - ) -(options, args) = options.parse_args(sys.argv) +def get_options(): + optparser = optparse.OptionParser() + 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 -providers = [] -if options.tracepoints: - providers.append(TracepointProvider()) -if options.debugfs: - providers.append(DebugfsProvider()) +def get_providers(options): + providers = [] -if len(providers) == 0: - try: - providers = [TracepointProvider()] - except: - providers = [DebugfsProvider()] + if options.tracepoints: + providers.append(TracepointProvider()) + if options.debugfs: + providers.append(DebugfsProvider()) + if len(providers) == 0: + providers.append(TracepointProvider()) -stats = Stats(providers, fields = options.fields) + return providers -if options.log: - log(stats) -elif not options.once: - curses.wrapper(tui, stats) -else: - batch(stats) +def check_access(): + 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): + sys.stderr.write("Please make {0} readable by the current user.\n" + .format(PATH_DEBUGFS_TRACING)) + sys.exit(1) + +def main(): + check_access() + detect_platform() + options = get_options() + providers = get_providers(options) + stats = Stats(providers, fields = options.fields) + + if options.log: + log(stats) + elif not options.once: + curses.wrapper(tui, stats) + else: + batch(stats) + +if __name__ == "__main__": + main()