benchmarks: add rpc_timing

benchmarks/all.py

@@ -1,9 +1,9 @@
 from artiq import *
 
-import pulse_rate, rtio_skew
+import pulse_rate, rtio_skew, rpc_timing
 
 
-_units = [pulse_rate.PulseRate, rtio_skew.RTIOSkew]
+_units = [pulse_rate.PulseRate, rtio_skew.RTIOSkew, rpc_timing.RPCTiming]
 
 class AllBenchmarks(AutoDB):
     def build(self):

benchmarks/rpc_timing.py

@@ -0,0 +1,29 @@
+from math import sqrt
+
+from artiq import *
+
+
+class RPCTiming(AutoDB):
+    class DBKeys:
+        repeats = Argument(100)
+        rpc_time_mean = Result()
+        rpc_time_stddev = Result()
+
+    def nop(self, x):
+        pass
+
+    @kernel
+    def bench(self):
+        self.ts = [0.0 for _ in range(self.repeats)]
+        for i in range(self.repeats):
+            t1 = self.core.get_rtio_time()
+            self.nop(10)
+            t2 = self.core.get_rtio_time()
+            self.ts[i] = float(t2.amount - t1.amount)
+
+    def run(self):
+        self.bench()
+        mean = sum(self.ts)/self.repeats
+        self.rpc_time_stddev = sqrt(
+            sum([(t - mean)**2 for t in self.ts]))/self.repeats*s
+        self.rpc_time_mean = mean*s