From a013bd2f7b88c831241b3ad6d5635e9d13a7e3fc Mon Sep 17 00:00:00 2001 From: Janosch Frank Date: Mon, 11 Jan 2016 16:18:04 +0100 Subject: scripts/kvm/kvm_stat: Add optparse description Added a description text that explains what the script does and which requirements have to be met to let it run. The help formatter class is needed as the default optparse formatter makes the text unreadable. Signed-off-by: Janosch Frank Message-Id: <1452525484-32309-35-git-send-email-frankja@linux.vnet.ibm.com> Signed-off-by: Paolo Bonzini --- scripts/kvm/kvm_stat | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) (limited to 'scripts/kvm') 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, -- cgit v1.2.1