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authorJanosch Frank <frankja@linux.vnet.ibm.com>2016-01-11 16:18:04 +0100
committerTimothy Pearson <tpearson@raptorengineering.com>2019-11-29 19:29:55 -0600
commita4591ee848dd955baa7811f77768da6821f4a546 (patch)
tree71df88ec37d04a53a4be473fb2a1b151f08a7517
parent8072b7583490c5ecf01a58e6f8e5c6c0a4459fd6 (diff)
downloadhqemu-a4591ee848dd955baa7811f77768da6821f4a546.zip
hqemu-a4591ee848dd955baa7811f77768da6821f4a546.tar.gz
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 <frankja@linux.vnet.ibm.com> Message-Id: <1452525484-32309-35-git-send-email-frankja@linux.vnet.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rwxr-xr-xscripts/kvm/kvm_stat29
1 files changed, 28 insertions, 1 deletions
diff --git a/scripts/kvm/kvm_stat b/scripts/kvm/kvm_stat
index 25631a4..d43e8f3 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,
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