Create a script for processing trace data

util/latency_report.py

@@ -0,0 +1,74 @@
+#!/usr/bin/python
+
+import os
+import math
+
+stream = os.popen('perf script -F time,event')
+
+is_in_update_fb = False
+
+class StateTracker:
+    def __init__(self, name, src, enter, leave):
+        self.is_active = False
+        self.name = name
+        self.src = src
+        self.enter = enter
+        self.leave = leave
+        self.n = 0
+        self.dt_sum = 0.0
+        self.dt_square_sum = 0.0
+        self.dt_max = 0.0
+        self.dt_min = math.inf
+
+    def add_dt(self, dt):
+        self.n += 1
+        self.dt_sum += dt
+        self.dt_square_sum += dt ** 2
+        self.dt_max = max(self.dt_max, dt)
+        self.dt_min = min(self.dt_min, dt)
+
+    def apply(self, src, event, t):
+        if self.is_active:
+            if (src, event) == (self.src, self.leave):
+                self.is_active = False
+                self.add_dt(t - self.t0)
+        else:
+            if (src, event) == (self.src, self.enter):
+                self.is_active = True
+                self.t0 = t
+
+    def avg(self):
+        return self.dt_sum / self.n
+
+    def var(self):
+        return self.dt_square_sum / self.n - self.avg() ** 2
+
+    def stddev(self):
+        return math.sqrt(self.var())
+
+    def report(self):
+        if self.n == 0:
+            return
+
+        print('{}:'.format(self.name))
+        print('\tMin, max: {:.1f} ms, {:.1f} ms'.format(self.dt_min * 1e3, self.dt_max * 1e3))
+        print('\tAverage, std.dev.: {:.1f} ms, {:.1f} ms'.format(self.avg() * 1e3, self.stddev() * 1e3))
+
+trackers = [
+    StateTracker('Framebuffer update', 'sdt_neatvnc', 'update_fb_start', 'update_fb_done'),
+    StateTracker('Screencopy', 'sdt_wayvnc', 'screencopy_start', 'screencopy_ready'),
+    StateTracker('Render', 'sdt_wayvnc', 'render_framebuffer_start', 'render_framebuffer_end'),
+    StateTracker('Copy damage map', 'sdt_wayvnc', 'render_read_damage_start', 'render_read_damage_end'),
+    StateTracker('Copy frame pixels', 'sdt_wayvnc', 'render_read_frame_start', 'render_read_frame_end'),
+]
+
+for line in stream:
+    [t, src, event, _] = line.replace(' ', '').split(':')
+    t = float(t)
+
+    for tracker in trackers:
+        tracker.apply(src, event, t)
+
+for tracker in trackers:
+    tracker.report()
+    print()