Define a Python class to be used for easy manipulation of kernel
histograms.
Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@xxxxxxxxx>
---
tracecruncher/ft_utils.py | 124 ++++++++++++++++++++++++++++++++++++++
1 file changed, 124 insertions(+)
diff --git a/tracecruncher/ft_utils.py b/tracecruncher/ft_utils.py
index cae54b0..ed4bdcd 100644
--- a/tracecruncher/ft_utils.py
+++ b/tracecruncher/ft_utils.py
@@ -210,3 +210,127 @@ class kretval_probe(kprobe_base):
"""
self.kp = ft.register_kprobe(event=self.name, function=self.func);
self.evt_id = find_event_id(system=ft.tc_event_system(), event=self.name)
+
+
+class khist:
+ def __init__(self, name, event, axes, weights=[],
+ sort_keys=[], sort_dir={}, find=False):
+ """ Constructor.
+ """
+ self.name = name
+ self.inst = None
+
+ inst_name = name+'_inst'
+ if find:
+ self.inst = ft.find_instance(name=inst_name)
+ self.attached = False
+ else:
+ self.inst = ft.create_instance(name=inst_name)
+ self.attached = True
+
+ self.hist = ft.hist(name=name,
+ system=event.system,
+ event=event.name,
+ axes=axes)
+
+ for v in weights:
+ self.hist.add_value(value=v)
+
+ self.hist.sort_keys(keys=sort_keys)
+
+ for key, val in sort_dir.items():
+ self.hist.sort_key_direction(sort_key=key,
+ direction=val)
+
+ self.trigger = '{0}/events/{1}/{2}/trigger'.format(self.inst.dir(),
+ event.system,
+ event.name)
+
+ if not find:
+ # Put the kernel histogram on 'standby'
+ self.hist.stop(self.inst)
+
+ def __del__(self):
+ """ Destructor.
+ """
+ if self.inst and self.attached:
+ self.clear()
+
+ def start(self):
+ """ Start accumulating data.
+ """
+ self.hist.resume(self.inst)
+
+ def stop(self):
+ """ Stop accumulating data.
+ """
+ self.hist.stop(self.inst)
+
+ def resume(self):
+ """ Continue accumulating data.
+ """
+ self.hist.resume(self.inst)
+
+ def data(self):
+ """ Read the accumulated data.
+ """
+ return self.hist.read(self.inst)
+
+ def clear(self):
+ """ Clear the accumulated data.
+ """
+ self.hist.clear(self.inst)
+
+ def detach(self):
+ """ Detach the object from the Python module.
+ """
+ ft.detach(self.inst)
+ self.attached = False
+
+ def attach(self):
+ """ Attach the object to the Python module.
+ """
+ ft.attach(self.inst)
+ self.attached = True
+
+ def is_attached(self):
+ """ Check if the object is attached to the Python module.
+ """
+ return self.attached
+
+ def __repr__(self):
+ """ Read the descriptor of the histogram.
+ """
+ with open(self.trigger) as f:
+ return f.read().rstrip()
+
+ def __str__(self):
+ return self.data()
+
+
+def create_khist(name, event, axes, weights=[],
+ sort_keys=[], sort_dir={}):
+ """ Create new kernel histogram.
+ """
+ try:
+ hist = khist(name=name, event=event, axes=axes, weights=weights,
+ sort_keys=sort_keys, sort_dir=sort_dir, find=False)
+ except Exception as err:
+ msg = 'Failed to create histogram \'{0}\''.format(name)
+ raise RuntimeError(msg) from err
+
+ return hist
+
+
+def find_khist(name, event, axes, instance=None,
+ weights=[], sort_keys=[], sort_dir={}):
+ """ Find existing kernel histogram.
+ """
+ try:
+ hist = khist(name=name, event=event, axes=axes, weights=weights,
+ sort_keys=sort_keys, sort_dir=sort_dir, find=True)
+ except Exception as err:
+ msg = 'Failed to find histogram \'{0}\''.format(name)
+ raise RuntimeError(msg) from err
+
+ return hist
--
2.32.0
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