diff --git a/scripts/kvm/kvm_stat b/scripts/kvm/kvm_stat index 25631a49f7..d43e8f3e85 100755 --- a/scripts/kvm/kvm_stat +++ b/scripts/kvm/kvm_stat @@ -705,7 +705,34 @@ def log(stats): line += 1 def get_options(): - optparser = optparse.OptionParser() + 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,