[PATCH 3/7] tools/kvm_stat: add command line switch '-s' to set update interval

Stefan Raspl
2020-03-06T11:43:01Z

From: Stefan Raspl <raspl@de.ibm.com>

This now controls both, the refresh rate of the interactive mode as well
as the logging mode. Which, as a consequence, means that the default of
logging mode is now 3s, too (use command line switch '-s' to adjust to
your liking).

Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
---
tools/kvm/kvm_stat/kvm_stat | 46 ++++++++++++++++++++++++---------
tools/kvm/kvm_stat/kvm_stat.txt | 4 +++
2 files changed, 38 insertions(+), 12 deletions(-)

diff --git a/tools/kvm/kvm_stat/kvm_stat b/tools/kvm/kvm_stat/kvm_stat
index 2d9947f596fc..8ed25bf1d048 100755
--- a/tools/kvm/kvm_stat/kvm_stat
+++ b/tools/kvm/kvm_stat/kvm_stat
@@ -970,15 +970,17 @@ DELAY_DEFAULT = 3.0
MAX_GUEST_NAME_LEN = 48
MAX_REGEX_LEN = 44
SORT_DEFAULT = 0
+MIN_DELAY = 0.1
+MAX_DELAY = 25.5

class Tui(object):
"""Instruments curses to draw a nice text ui."""
- def __init__(self, stats):
+ def __init__(self, stats, opts):
self.stats = stats
self.screen = None
self._delay_initial = 0.25
- self._delay_regular = DELAY_DEFAULT
+ self._delay_regular = opts.set_delay
self._sorting = SORT_DEFAULT
self._display_guests = 0

@@ -1278,7 +1280,8 @@ class Tui(object):
' p filter by guest name/PID',
' q quit',
' r reset stats',
- ' s set update interval',
+ ' s set delay between refreshs (value range: '
+ '%s-%s secs)' % (MIN_DELAY, MAX_DELAY),
' x toggle reporting of stats for individual child trace'
' events',
'Any other key refreshes statistics immediately')
@@ -1344,11 +1347,9 @@ class Tui(object):
try:
if len(val) > 0:
delay = float(val)
- if delay < 0.1:
- msg = '"' + str(val) + '": Value must be >=0.1'
- continue
- if delay > 25.5:
- msg = '"' + str(val) + '": Value must be <=25.5'
+ err = is_delay_valid(delay)
+ if err is not None:
+ msg = err
continue
else:
delay = DELAY_DEFAULT
@@ -1484,7 +1485,7 @@ def batch(stats):
pass

-def log(stats):
+def log(stats, opts):
"""Prints statistics as reiterating key block, multiple value blocks."""
keys = sorted(stats.get().keys())

@@ -1502,7 +1503,7 @@ def log(stats):
banner_repeat = 20
while True:
try:
- time.sleep(1)
+ time.sleep(opts.set_delay)
if line % banner_repeat == 0:
banner()
statline()
@@ -1511,6 +1512,16 @@ def log(stats):
break

+def is_delay_valid(delay):
+ """Verify delay is in valid value range."""
+ msg = None
+ if delay < MIN_DELAY:
+ msg = '"' + str(delay) + '": Delay must be >=%s' % MIN_DELAY
+ if delay > MAX_DELAY:
+ msg = '"' + str(delay) + '": Delay must be <=%s' % MAX_DELAY
+ return msg
+
+
def get_options():
"""Returns processed program arguments."""
description_text = """
@@ -1600,6 +1611,13 @@ Press any other key to refresh statistics immediately.
default=0,
help='restrict statistics to pid',
)
+ argparser.add_argument('-s', '--set-delay',
+ type=float,
+ default=DELAY_DEFAULT,
+ metavar='DELAY',
+ help='set delay between refreshs (value range: '
+ '%s-%s secs)' % (MIN_DELAY, MAX_DELAY),
+ )
argparser.add_argument('-t', '--tracepoints',
action='store_true',
default=False,
@@ -1671,6 +1689,10 @@ def main():
sys.stderr.write('Did you use a (unsupported) tid instead of a pid?\n')
sys.exit('Specified pid does not exist.')

+ err = is_delay_valid(options.set_delay)
+ if err is not None:
+ sys.exit('Error: ' + err)
+
stats = Stats(options)

if options.fields == 'help':
@@ -1682,9 +1704,9 @@ def main():
sys.exit(0)

if options.log:
- log(stats)
+ log(stats, options)
elif not options.once:
- with Tui(stats) as tui:
+ with Tui(stats, options) as tui:
tui.show_stats()
else:
batch(stats)
diff --git a/tools/kvm/kvm_stat/kvm_stat.txt b/tools/kvm/kvm_stat/kvm_stat.txt
index 8e0658e79eb7..20928057cc9e 100644
--- a/tools/kvm/kvm_stat/kvm_stat.txt
+++ b/tools/kvm/kvm_stat/kvm_stat.txt
@@ -92,6 +92,10 @@ OPTIONS
--pid=<pid>::
limit statistics to one virtual machine (pid)

+-s::
+--set-delay::
+ set delay between refreshs (value range: 0.1-25.5 secs)
+
-t::
--tracepoints::
retrieve statistics from tracepoints
--
2.17.1