[PATCH v1 43/58] perf sched-migration: Port sched-migration/SchedGui to use python module

Ian Rogers
2026-04-20T00:01:02Z

Ported from tools/perf/scripts/python/ and its Util lib.
- Refactored sched-migration.py to use a class structure
(SchedMigrationAnalyzer) to encapsulate state.
- Used perf.session for event processing.
- Ported SchedGui.py to the same directory to keep it as a local
dependency.
- Made wxPython dependency optional in sched-migration.py, printing a
message if it's missing instead of failing with ImportError.
- Cleaned up Python 2 compatibility artifacts.

Assisted-by: Gemini:gemini-3.1-pro-preview
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/python/SchedGui.py | 180 +++++++++++
tools/perf/python/sched-migration.py | 466 +++++++++++++++++++++++++++
2 files changed, 646 insertions(+)
create mode 100755 tools/perf/python/SchedGui.py
create mode 100755 tools/perf/python/sched-migration.py

diff --git a/tools/perf/python/SchedGui.py b/tools/perf/python/SchedGui.py
new file mode 100755
index 000000000000..321b25854883
--- /dev/null
+++ b/tools/perf/python/SchedGui.py
@@ -0,0 +1,180 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+# SchedGui.py - Python extension for perf script, basic GUI code for
+# traces drawing and overview.
+#
+# Copyright (C) 2010 by Frederic Weisbecker <fweisbec@gmail.com>
+#
+# Ported to modern directory structure.
+
+try:
+ import wx
+except ImportError:
+ raise ImportError("You need to install the wxpython lib for this script")
+
+
+class RootFrame(wx.Frame):
+ Y_OFFSET = 100
+ RECT_HEIGHT = 100
+ RECT_SPACE = 50
+ EVENT_MARKING_WIDTH = 5
+
+ def __init__(self, sched_tracer, title, parent=None, id=-1):
+ wx.Frame.__init__(self, parent, id, title)
+
+ (self.screen_width, self.screen_height) = wx.GetDisplaySize()
+ self.screen_width -= 10
+ self.screen_height -= 10
+ self.zoom = 0.5
+ self.scroll_scale = 20
+ self.sched_tracer = sched_tracer
+ self.sched_tracer.set_root_win(self)
+ (self.ts_start, self.ts_end) = sched_tracer.interval()
+ self.update_width_virtual()
+ self.nr_rects = sched_tracer.nr_rectangles() + 1
+ self.height_virtual = RootFrame.Y_OFFSET + (self.nr_rects * (RootFrame.RECT_HEIGHT + RootFrame.RECT_SPACE))
+
+ # whole window panel
+ self.panel = wx.Panel(self, size=(self.screen_width, self.screen_height))
+
+ # scrollable container
+ self.scroll = wx.ScrolledWindow(self.panel)
+ self.scroll.SetScrollbars(self.scroll_scale, self.scroll_scale, self.width_virtual / self.scroll_scale, self.height_virtual / self.scroll_scale)
+ self.scroll.EnableScrolling(True, True)
+ self.scroll.SetFocus()
+
+ # scrollable drawing area
+ self.scroll_panel = wx.Panel(self.scroll, size=(self.screen_width - 15, self.screen_height / 2))
+ self.scroll_panel.Bind(wx.EVT_PAINT, self.on_paint)
+ self.scroll_panel.Bind(wx.EVT_KEY_DOWN, self.on_key_press)
+ self.scroll_panel.Bind(wx.EVT_LEFT_DOWN, self.on_mouse_down)
+ self.scroll.Bind(wx.EVT_PAINT, self.on_paint)
+ self.scroll.Bind(wx.EVT_KEY_DOWN, self.on_key_press)
+ self.scroll.Bind(wx.EVT_LEFT_DOWN, self.on_mouse_down)
+
+ self.scroll.Fit()
+ self.Fit()
+
+ self.scroll_panel.SetDimensions(-1, -1, self.width_virtual, self.height_virtual, wx.SIZE_USE_EXISTING)
+
+ self.txt = None
+
+ self.Show(True)
+
+ def us_to_px(self, val):
+ return val / (10 ** 3) * self.zoom
+
+ def px_to_us(self, val):
+ return (val / self.zoom) * (10 ** 3)
+
+ def scroll_start(self):
+ (x, y) = self.scroll.GetViewStart()
+ return (x * self.scroll_scale, y * self.scroll_scale)
+
+ def scroll_start_us(self):
+ (x, y) = self.scroll_start()
+ return self.px_to_us(x)
+
+ def paint_rectangle_zone(self, nr, color, top_color, start, end):
+ offset_px = self.us_to_px(start - self.ts_start)
+ width_px = self.us_to_px(end - self.ts_start)
+
+ offset_py = RootFrame.Y_OFFSET + (nr * (RootFrame.RECT_HEIGHT + RootFrame.RECT_SPACE))
+ width_py = RootFrame.RECT_HEIGHT
+
+ dc = self.dc
+
+ if top_color is not None:
+ (r, g, b) = top_color
+ top_color = wx.Colour(r, g, b)
+ brush = wx.Brush(top_color, wx.SOLID)
+ dc.SetBrush(brush)
+ dc.DrawRectangle(offset_px, offset_py, width_px, RootFrame.EVENT_MARKING_WIDTH)
+ width_py -= RootFrame.EVENT_MARKING_WIDTH
+ offset_py += RootFrame.EVENT_MARKING_WIDTH
+
+ (r, g, b) = color
+ color = wx.Colour(r, g, b)
+ brush = wx.Brush(color, wx.SOLID)
+ dc.SetBrush(brush)
+ dc.DrawRectangle(offset_px, offset_py, width_px, width_py)
+
+ def update_rectangles(self, dc, start, end):
+ start += self.ts_start
+ end += self.ts_start
+ self.sched_tracer.fill_zone(start, end)
+
+ def on_paint(self, event):
+ dc = wx.PaintDC(self.scroll_panel)
+ self.dc = dc
+
+ width = min(self.width_virtual, self.screen_width)
+ (x, y) = self.scroll_start()
+ start = self.px_to_us(x)
+ end = self.px_to_us(x + width)
+ self.update_rectangles(dc, start, end)
+
+ def rect_from_ypixel(self, y):
+ y -= RootFrame.Y_OFFSET
+ rect = y / (RootFrame.RECT_HEIGHT + RootFrame.RECT_SPACE)
+ height = y % (RootFrame.RECT_HEIGHT + RootFrame.RECT_SPACE)
+
+ if rect < 0 or rect > self.nr_rects - 1 or height > RootFrame.RECT_HEIGHT:
+ return -1
+
+ return rect
+
+ def update_summary(self, txt):
+ if self.txt:
+ self.txt.Destroy()
+ self.txt = wx.StaticText(self.panel, -1, txt, (0, (self.screen_height / 2) + 50))
+
+ def on_mouse_down(self, event):
+ (x, y) = event.GetPositionTuple()
+ rect = self.rect_from_ypixel(y)
+ if rect == -1:
+ return
+
+ t = self.px_to_us(x) + self.ts_start
+
+ self.sched_tracer.mouse_down(rect, t)
+
+ def update_width_virtual(self):
+ self.width_virtual = self.us_to_px(self.ts_end - self.ts_start)
+
+ def __zoom(self, x):
+ self.update_width_virtual()
+ (xpos, ypos) = self.scroll.GetViewStart()
+ xpos = self.us_to_px(x) / self.scroll_scale
+ self.scroll.SetScrollbars(self.scroll_scale, self.scroll_scale, self.width_virtual / self.scroll_scale, self.height_virtual / self.scroll_scale, xpos, ypos)
+ self.Refresh()
+
+ def zoom_in(self):
+ x = self.scroll_start_us()
+ self.zoom *= 2
+ self.__zoom(x)
+
+ def zoom_out(self):
+ x = self.scroll_start_us()
+ self.zoom /= 2
+ self.__zoom(x)
+
+ def on_key_press(self, event):
+ key = event.GetRawKeyCode()
+ if key == ord("+"):
+ self.zoom_in()
+ return
+ if key == ord("-"):
+ self.zoom_out()
+ return
+
+ key = event.GetKeyCode()
+ (x, y) = self.scroll.GetViewStart()
+ if key == wx.WXK_RIGHT:
+ self.scroll.Scroll(x + 1, y)
+ elif key == wx.WXK_LEFT:
+ self.scroll.Scroll(x - 1, y)
+ elif key == wx.WXK_DOWN:
+ self.scroll.Scroll(x, y + 1)
+ elif key == wx.WXK_UP:
+ self.scroll.Scroll(x, y - 1)
diff --git a/tools/perf/python/sched-migration.py b/tools/perf/python/sched-migration.py
new file mode 100755
index 000000000000..299c8b44064b
--- /dev/null
+++ b/tools/perf/python/sched-migration.py
@@ -0,0 +1,466 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+"""
+Cpu task migration overview toy
+
+Copyright (C) 2010 Frederic Weisbecker <fweisbec@gmail.com>
+Ported to modern directory structure and refactored to use class.
+"""
+
+import argparse
+from collections import defaultdict, UserList
+import perf
+
+# SchedGui might not be available if wxPython is missing
+try:
+ from SchedGui import RootFrame
+ import wx # type: ignore
+ WX_AVAILABLE = True
+except ImportError:
+ WX_AVAILABLE = False
+
+# Global threads dictionary
+threads = defaultdict(lambda: "unknown")
+threads[0] = "idle"
+
+
+def thread_name(pid: int) -> str:
+ """Return thread name formatted with pid."""
+ return f"{threads[pid]}:{pid}"
+
+
+def task_state(state: int) -> str:
+ """Map task state integer to string."""
+ states = {
+ 0: "R",
+ 1: "S",
+ 2: "D",
+ 64: "DEAD"
+ }
+ return states.get(state, "Unknown")
+
+
+class RunqueueEventUnknown:
+ """Unknown runqueue event."""
+ @staticmethod
+ def color():
+ """Return color for event."""
+ return None
+
+ def __repr__(self):
+ return "unknown"
+
+
+class RunqueueEventSleep:
+ """Sleep runqueue event."""
+ @staticmethod
+ def color():
+ """Return color for event."""
+ return 0, 0, 0xff
+
+ def __init__(self, sleeper: int):
+ self.sleeper = sleeper
+
+ def __repr__(self):
+ return f"{thread_name(self.sleeper)} gone to sleep"
+
+
+class RunqueueEventWakeup:
+ """Wakeup runqueue event."""
+ @staticmethod
+ def color():
+ """Return color for event."""
+ return 0xff, 0xff, 0
+
+ def __init__(self, wakee: int):
+ self.wakee = wakee
+
+ def __repr__(self):
+ return f"{thread_name(self.wakee)} woke up"
+
+
+class RunqueueEventFork:
+ """Fork runqueue event."""
+ @staticmethod
+ def color():
+ """Return color for event."""
+ return 0, 0xff, 0
+
+ def __init__(self, child: int):
+ self.child = child
+
+ def __repr__(self):
+ return f"new forked task {thread_name(self.child)}"
+
+
+class RunqueueMigrateIn:
+ """Migrate in runqueue event."""
+ @staticmethod
+ def color():
+ """Return color for event."""
+ return 0, 0xf0, 0xff
+
+ def __init__(self, new: int):
+ self.new = new
+
+ def __repr__(self):
+ return f"task migrated in {thread_name(self.new)}"
+
+
+class RunqueueMigrateOut:
+ """Migrate out runqueue event."""
+ @staticmethod
+ def color():
+ """Return color for event."""
+ return 0xff, 0, 0xff
+
+ def __init__(self, old: int):
+ self.old = old
+
+ def __repr__(self):
+ return f"task migrated out {thread_name(self.old)}"
+
+
+class RunqueueSnapshot:
+ """Snapshot of runqueue state."""
+
+ def __init__(self, tasks=None, event=None):
+ if tasks is None:
+ tasks = (0,)
+ if event is None:
+ event = RunqueueEventUnknown()
+ self.tasks = tuple(tasks)
+ self.event = event
+
+ def sched_switch(self, prev: int, prev_state: int, next_pid: int):
+ """Handle sched switch in snapshot."""
+ if task_state(prev_state) == "R" and next_pid in self.tasks \
+ and prev in self.tasks:
+ return self
+
+ event = RunqueueEventUnknown()
+ if task_state(prev_state) != "R":
+ event = RunqueueEventSleep(prev) # type: ignore
+
+ next_tasks = list(self.tasks[:])
+ if prev in self.tasks:
+ if task_state(prev_state) != "R":
+ next_tasks.remove(prev)
+ elif task_state(prev_state) == "R":
+ next_tasks.append(prev)
+
+ if next_pid not in next_tasks:
+ next_tasks.append(next_pid)
+
+ return RunqueueSnapshot(next_tasks, event)
+
+ def migrate_out(self, old: int):
+ """Handle task migrate out in snapshot."""
+ if old not in self.tasks:
+ return self
+ next_tasks = [task for task in self.tasks if task != old]
+
+ return RunqueueSnapshot(next_tasks, RunqueueMigrateOut(old))
+
+ def __migrate_in(self, new: int, event):
+ if new in self.tasks:
+ self.event = event
+ return self
+ next_tasks = self.tasks + tuple([new])
+
+ return RunqueueSnapshot(next_tasks, event)
+
+ def migrate_in(self, new: int):
+ """Handle task migrate in in snapshot."""
+ return self.__migrate_in(new, RunqueueMigrateIn(new))
+
+ def wake_up(self, new: int):
+ """Handle task wakeup in snapshot."""
+ return self.__migrate_in(new, RunqueueEventWakeup(new))
+
+ def wake_up_new(self, new: int):
+ """Handle task fork in snapshot."""
+ return self.__migrate_in(new, RunqueueEventFork(new))
+
+ def load(self) -> int:
+ """Provide the number of tasks on the runqueue. Don't count idle"""
+ return len(self.tasks) - 1
+
+ def __repr__(self):
+ return self.tasks.__repr__()
+
+
+class TimeSlice:
+ """Represents a time slice of execution."""
+
+ def __init__(self, start: int, prev):
+ self.start = start
+ self.prev = prev
+ self.end = start
+ # cpus that triggered the event
+ self.event_cpus: list[int] = []
+ if prev is not None:
+ self.total_load = prev.total_load
+ self.rqs = prev.rqs.copy()
+ else:
+ self.rqs = defaultdict(RunqueueSnapshot)
+ self.total_load = 0
+
+ def __update_total_load(self, old_rq: RunqueueSnapshot, new_rq: RunqueueSnapshot):
+ diff = new_rq.load() - old_rq.load()
+ self.total_load += diff
+
+ def sched_switch(self, ts_list, prev: int, prev_state: int, next_pid: int, cpu: int):
+ """Process sched_switch in time slice."""
+ old_rq = self.prev.rqs[cpu]
+ new_rq = old_rq.sched_switch(prev, prev_state, next_pid)
+
+ if old_rq is new_rq:
+ return
+
+ self.rqs[cpu] = new_rq
+ self.__update_total_load(old_rq, new_rq)
+ ts_list.append(self)
+ self.event_cpus = [cpu]
+
+ def migrate(self, ts_list, new: int, old_cpu: int, new_cpu: int):
+ """Process task migration in time slice."""
+ if old_cpu == new_cpu:
+ return
+ old_rq = self.prev.rqs[old_cpu]
+ out_rq = old_rq.migrate_out(new)
+ self.rqs[old_cpu] = out_rq
+ self.__update_total_load(old_rq, out_rq)
+
+ new_rq = self.prev.rqs[new_cpu]
+ in_rq = new_rq.migrate_in(new)
+ self.rqs[new_cpu] = in_rq
+ self.__update_total_load(new_rq, in_rq)
+
+ ts_list.append(self)
+
+ if old_rq is not out_rq:
+ self.event_cpus.append(old_cpu)
+ self.event_cpus.append(new_cpu)
+
+ def wake_up(self, ts_list, pid: int, cpu: int, fork: bool):
+ """Process wakeup in time slice."""
+ old_rq = self.prev.rqs[cpu]
+ if fork:
+ new_rq = old_rq.wake_up_new(pid)
+ else:
+ new_rq = old_rq.wake_up(pid)
+
+ if new_rq is old_rq:
+ return
+ self.rqs[cpu] = new_rq
+ self.__update_total_load(old_rq, new_rq)
+ ts_list.append(self)
+ self.event_cpus = [cpu]
+
+ def next(self, t: int):
+ """Create next time slice."""
+ self.end = t
+ return TimeSlice(t, self)
+
+
+class TimeSliceList(UserList):
+ """List of time slices with search capabilities."""
+
+ def __init__(self, arg=None):
+ super().__init__(arg if arg is not None else [])
+ self.root_win = None
+
+ def get_time_slice(self, ts: int) -> TimeSlice:
+ """Get or create time slice for timestamp."""
+ if len(self.data) == 0:
+ ts_slice = TimeSlice(ts, TimeSlice(-1, None))
+ else:
+ ts_slice = self.data[-1].next(ts)
+ return ts_slice
+
+ def find_time_slice(self, ts: int) -> int:
+ """Binary search for time slice containing timestamp."""
+ start = 0
+ end = len(self.data)
+ found = -1
+ searching = True
+ while searching:
+ if start in (end, end - 1):
+ searching = False
+
+ i = (end + start) // 2
+ if self.data[i].start <= ts <= self.data[i].end:
+ found = i
+ break
+
+ if self.data[i].end < ts:
+ start = i
+ elif self.data[i].start > ts:
+ end = i
+
+ return found
+
+ def set_root_win(self, win):
+ """Set root window for GUI."""
+ self.root_win = win
+
+ def mouse_down(self, cpu: int, t: int):
+ """Handle mouse down event from GUI."""
+ idx = self.find_time_slice(t)
+ if idx == -1:
+ return
+
+ ts = self[idx]
+ rq = ts.rqs[cpu]
+ raw = f"CPU: {cpu}\n"
+ raw += f"Last event : {repr(rq.event)}\n"
+ raw += f"Timestamp : {ts.start // (10 ** 9)}.{ts.start % (10 ** 9) // 1000:06d}\n"
+ raw += f"Duration : {(ts.end - ts.start) // (10 ** 6):6d} us\n"
+ raw += f"Load = {rq.load()}\n"
+ for task in rq.tasks:
+ raw += f"{thread_name(task)} \n"
+
+ if self.root_win:
+ self.root_win.update_summary(raw)
+
+ def update_rectangle_cpu(self, slice_obj: TimeSlice, cpu: int):
+ """Update rectangle for CPU in GUI."""
+ rq = slice_obj.rqs[cpu]
+
+ if slice_obj.total_load != 0:
+ load_rate = rq.load() / float(slice_obj.total_load)
+ else:
+ load_rate = 0
+
+ red_power = int(0xff - (0xff * load_rate))
+ color = (0xff, red_power, red_power)
+
+ top_color = None
+ if cpu in slice_obj.event_cpus:
+ top_color = rq.event.color()
+
+ if self.root_win:
+ self.root_win.paint_rectangle_zone(cpu, color, top_color,
+ slice_obj.start, slice_obj.end)
+
+ def fill_zone(self, start: int, end: int):
+ """Fill zone in GUI."""
+ i = self.find_time_slice(start)
+ if i == -1:
+ return
+
+ for idx in range(i, len(self.data)):
+ timeslice = self.data[idx]
+ if timeslice.start > end:
+ return
+
+ for cpu in timeslice.rqs:
+ self.update_rectangle_cpu(timeslice, cpu)
+
+ def interval(self) -> tuple[int, int]:
+ """Return start and end timestamps."""
+ if len(self.data) == 0:
+ return 0, 0
+ return self.data[0].start, self.data[-1].end
+
+ def nr_rectangles(self) -> int:
+ """Return maximum CPU number."""
+ last_ts = self.data[-1]
+ max_cpu = 0
+ for cpu in last_ts.rqs:
+ max_cpu = max(max_cpu, cpu)
+ return max_cpu
+
+
+class SchedMigrationAnalyzer:
+ """Analyzes task migrations and manages time slices."""
+
+ def __init__(self):
+ self.current_tsk = defaultdict(lambda: -1)
+ self.timeslices = TimeSliceList()
+
+ def sched_switch(self, time: int, cpu: int, prev_comm: str, prev_pid: int, prev_state: int,
+ next_comm: str, next_pid: int):
+ """Handle sched_switch event."""
+ on_cpu_task = self.current_tsk[cpu]
+
+ if on_cpu_task not in (-1, prev_pid):
+ print(f"Sched switch event rejected ts: {time} cpu: {cpu} "
+ f"prev: {prev_comm}({prev_pid}) next: {next_comm}({next_pid})")
+
+ threads[prev_pid] = prev_comm
+ threads[next_pid] = next_comm
+ self.current_tsk[cpu] = next_pid
+
+ ts = self.timeslices.get_time_slice(time)
+ ts.sched_switch(self.timeslices, prev_pid, prev_state, next_pid, cpu)
+
+ def migrate(self, time: int, pid: int, orig_cpu: int, dest_cpu: int):
+ """Handle sched_migrate_task event."""
+ ts = self.timeslices.get_time_slice(time)
+ ts.migrate(self.timeslices, pid, orig_cpu, dest_cpu)
+
+ def wake_up(self, time: int, pid: int, success: int, target_cpu: int, fork: bool):
+ """Handle wakeup event."""
+ if success == 0:
+ return
+ ts = self.timeslices.get_time_slice(time)
+ ts.wake_up(self.timeslices, pid, target_cpu, fork)
+
+ def process_event(self, sample: perf.sample_event) -> None:
+ """Collect events and pass to analyzer."""
+ name = str(sample.evsel)
+ time = sample.sample_time
+ cpu = sample.sample_cpu
+ _pid = sample.sample_pid
+ _comm = getattr(sample, "comm", "Unknown")
+
+ if name == "evsel(sched:sched_switch)":
+ prev_comm = getattr(sample, "prev_comm", "Unknown")
+ prev_pid = getattr(sample, "prev_pid", -1)
+ prev_state = getattr(sample, "prev_state", 0)
+ next_comm = getattr(sample, "next_comm", "Unknown")
+ next_pid = getattr(sample, "next_pid", -1)
+ self.sched_switch(time, cpu, prev_comm, prev_pid, prev_state, next_comm, next_pid)
+ elif name == "evsel(sched:sched_migrate_task)":
+ task_pid = getattr(sample, "pid", -1)
+ orig_cpu = getattr(sample, "orig_cpu", -1)
+ dest_cpu = getattr(sample, "dest_cpu", -1)
+ self.migrate(time, task_pid, orig_cpu, dest_cpu)
+ elif name == "evsel(sched:sched_wakeup)":
+ task_pid = getattr(sample, "pid", -1)
+ success = getattr(sample, "success", 1)
+ target_cpu = getattr(sample, "target_cpu", -1)
+ self.wake_up(time, task_pid, success, target_cpu, False)
+ elif name == "evsel(sched:sched_wakeup_new)":
+ task_pid = getattr(sample, "pid", -1)
+ success = getattr(sample, "success", 1)
+ target_cpu = getattr(sample, "target_cpu", -1)
+ self.wake_up(time, task_pid, success, target_cpu, True)
+
+ def run_gui(self):
+ """Start wxPython GUI."""
+ if not WX_AVAILABLE:
+ print("wxPython is not available. Cannot start GUI.")
+ return
+ app = wx.App(False)
+ _frame = RootFrame(self.timeslices, "Migration")
+ app.MainLoop()
+
+
+if __name__ == "__main__":
+ ap = argparse.ArgumentParser(description="Cpu task migration overview toy")
+ ap.add_argument("-i", "--input", default="perf.data", help="Input file name")
+ args = ap.parse_args()
+
+ analyzer = SchedMigrationAnalyzer()
+
+ try:
+ session = perf.session(perf.data(args.input), sample=analyzer.process_event)
+ session.process_events()
+ analyzer.run_gui()
+ except KeyboardInterrupt:
+ pass
+ except Exception as e:
+ print(f"Error processing events: {e}")
--
2.54.0.rc1.513.gad8abe7a5a-goog