cpufreq/time_in_state: add time_in_state support
Get the time_in_state for all cpus by cluster. Add option to
compute the delta between two time_in_states. This can be used
in determining how much power the cpu used over a period of time.
Test: call cpufreq.get_time_in_state(clusters)
Change-Id: I173d269c486b476005563d3ffa4af29024b91a15
diff --git a/devlib/module/cpufreq.py b/devlib/module/cpufreq.py
index e18d95b..5e8c585 100644
--- a/devlib/module/cpufreq.py
+++ b/devlib/module/cpufreq.py
@@ -12,6 +12,7 @@
# See the License for the specific language governing permissions and
# limitations under the License.
#
+import json
from devlib.module import Module
from devlib.exception import TargetError
from devlib.utils.misc import memoized
@@ -434,3 +435,55 @@
domain = self.target.cpufreq.get_domain_cpus(cpu)
yield domain
cpus = cpus.difference(domain)
+
+ def get_time_in_state(self, clusters):
+ """
+ Gets the time at each frequency on each cluster
+ :param clusters: A list of clusters on the device. Each cluster is a
+ list of cpus on that cluster.
+ """
+ time_in_state_by_cluster = {}
+
+ for i, cluster in enumerate(clusters):
+ frequencies = self.list_frequencies(cluster[0])
+ time_in_state = dict((str(freq), 0) for freq in frequencies)
+
+ for cpu in cluster:
+ stats = self.target.execute('cat '\
+ '/sys/devices/system/cpu/cpu{}/cpufreq/stats'
+ '/time_in_state'.format(cpu))
+ for entry in stats.split('\n'):
+ if len(entry) > 0:
+ freq, time = entry.split(' ')
+ time_in_state[freq] += int(time)
+
+ time_in_state_by_cluster[str(i)] = time_in_state
+
+ return time_in_state_by_cluster
+
+ def dump_time_in_state_delta(self, start, clusters, dump_file):
+ """
+ Dumps the time between the stop and start by cluster by frequency
+ :param start: The inital output from a call to cpufreq.get_time_in_state
+ :param clusters: A list of clusters on the device. Each cluster is a
+ list of cpus on that cluster.
+ :param dump_file: A file to dump the delta time_in_state_delta to.
+ """
+ stop = self.get_time_in_state(clusters)
+
+ time_in_state_delta = {}
+
+ for cl in start:
+ time_in_state_delta[cl] = {}
+
+ for freq in start[cl].keys():
+ time_in_start = start[cl][freq]
+ time_in_stop = stop[cl][freq]
+ time_in_state_delta[cl][freq] = time_in_stop - time_in_start
+
+ output = {'time_delta' : time_in_state_delta,
+ 'clusters' : {str(i) : [str(c) for c in cl]
+ for i, cl in enumerate(clusters)}}
+
+ with open(dump_file, 'w') as dfile:
+ json.dump(output, dfile, indent=4, sort_keys=True)
