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authorStefan Raspl <raspl@linux.vnet.ibm.com>2017-03-10 13:40:15 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2017-03-29 12:01:32 +0200
commit9f114a03c6854f49065dd036c17e1b4bb947f842 (patch)
tree6a6021130500323dce2d6a98ae14cf5d2bd80e7b /tools
parent4443084fa0cf85f91d357c8917b90504b784d925 (diff)
tools/kvm_stat: add interactive command 'r'
Provide an interactive command to reset the tracepoint statistics. Requires some extra work for debugfs, as the counters cannot be reset. On the up side, this offers us the opportunity to have debugfs values reset on startup and whenever a filter is modified, becoming consistent with the tracepoint provider. As a bonus, 'kvmstat -dt' will now provide useful output, instead of mixing values in totally different orders of magnitude. Furthermore, we avoid unnecessary resets when any of the filters is "changed" interactively to the previous value. Signed-off-by: Stefan Raspl <raspl@linux.vnet.ibm.com> Acked-by: Janosch Frank <frankja@linux.vnet.ibm.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Diffstat (limited to 'tools')
-rwxr-xr-xtools/kvm/kvm_stat/kvm_stat65
-rw-r--r--tools/kvm/kvm_stat/kvm_stat.txt2
2 files changed, 53 insertions, 14 deletions
diff --git a/tools/kvm/kvm_stat/kvm_stat b/tools/kvm/kvm_stat/kvm_stat
index 676a92a4a12e..f8c48f8d07a7 100755
--- a/tools/kvm/kvm_stat/kvm_stat
+++ b/tools/kvm/kvm_stat/kvm_stat
@@ -716,15 +716,23 @@ class TracepointProvider(object):
ret[name] += val
return ret
+ def reset(self):
+ """Reset all field counters"""
+ for group in self.group_leaders:
+ for event in group.events:
+ event.reset()
+
class DebugfsProvider(object):
"""Provides data from the files that KVM creates in the kvm debugfs
folder."""
def __init__(self):
self._fields = self.get_available_fields()
+ self._baseline = {}
self._pid = 0
self.do_read = True
self.paths = []
+ self.reset()
def get_available_fields(self):
""""Returns a list of available fields.
@@ -741,6 +749,7 @@ class DebugfsProvider(object):
@fields.setter
def fields(self, fields):
self._fields = fields
+ self.reset()
@property
def pid(self):
@@ -758,10 +767,11 @@ class DebugfsProvider(object):
self.paths = filter(lambda x: "{}-".format(pid) in x, vms)
else:
- self.paths = ['']
+ self.paths = []
self.do_read = True
+ self.reset()
- def read(self):
+ def read(self, reset=0):
"""Returns a dict with format:'file name / field -> current value'."""
results = {}
@@ -769,10 +779,22 @@ class DebugfsProvider(object):
if not self.do_read:
return results
- for path in self.paths:
+ paths = self.paths
+ if self._pid == 0:
+ paths = []
+ for entry in os.walk(PATH_DEBUGFS_KVM):
+ for dir in entry[1]:
+ paths.append(dir)
+ for path in paths:
for field in self._fields:
- results[field] = results.get(field, 0) \
- + self.read_field(field, path)
+ value = self.read_field(field, path)
+ key = path + field
+ if reset:
+ self._baseline[key] = value
+ if self._baseline.get(key, -1) == -1:
+ self._baseline[key] = value
+ results[field] = (results.get(field, 0) + value -
+ self._baseline.get(key, 0))
return results
@@ -786,6 +808,11 @@ class DebugfsProvider(object):
except IOError:
return 0
+ def reset(self):
+ """Reset field counters"""
+ self._baseline = {}
+ self.read(1)
+
class Stats(object):
"""Manages the data providers and the data they provide.
@@ -822,14 +849,20 @@ class Stats(object):
for provider in self.providers:
provider.pid = self._pid_filter
+ def reset(self):
+ self.values = {}
+ for provider in self.providers:
+ provider.reset()
+
@property
def fields_filter(self):
return self._fields_filter
@fields_filter.setter
def fields_filter(self, fields_filter):
- self._fields_filter = fields_filter
- self.update_provider_filters()
+ if fields_filter != self._fields_filter:
+ self._fields_filter = fields_filter
+ self.update_provider_filters()
@property
def pid_filter(self):
@@ -837,9 +870,10 @@ class Stats(object):
@pid_filter.setter
def pid_filter(self, pid):
- self._pid_filter = pid
- self.values = {}
- self.update_provider_pid()
+ if pid != self._pid_filter:
+ self._pid_filter = pid
+ self.values = {}
+ self.update_provider_pid()
def get(self):
"""Returns a dict with field -> (value, delta to last value) of all
@@ -847,11 +881,9 @@ class Stats(object):
for provider in self.providers:
new = provider.read()
for key in provider.fields:
- oldval = self.values.get(key, (0, 0))
+ oldval = self.values.get(key, (0, 0))[0]
newval = new.get(key, 0)
- newdelta = None
- if oldval is not None:
- newdelta = newval - oldval[0]
+ newdelta = newval - oldval
self.values[key] = (newval, newdelta)
return self.values
@@ -1117,6 +1149,10 @@ class Tui(object):
if char == 'p':
self.show_vm_selection_by_pid()
sleeptime = DELAY_INITIAL
+ if char == 'r':
+ self.refresh_header()
+ self.stats.reset()
+ sleeptime = DELAY_INITIAL
except KeyboardInterrupt:
break
except curses.error:
@@ -1190,6 +1226,7 @@ Interactive Commands:
p filter by PID
q quit
x toggle reporting of stats for individual child trace events
+ r reset stats
Press any other key to refresh statistics immediately.
"""
diff --git a/tools/kvm/kvm_stat/kvm_stat.txt b/tools/kvm/kvm_stat/kvm_stat.txt
index c3ab6a2c8c37..109431bdc63c 100644
--- a/tools/kvm/kvm_stat/kvm_stat.txt
+++ b/tools/kvm/kvm_stat/kvm_stat.txt
@@ -39,6 +39,8 @@ INTERACTIVE COMMANDS
*q*:: quit
+*r*:: reset stats
+
*x*:: toggle reporting of stats for child trace events
Press any other key to refresh statistics immediately.