[PATCH v1] perf python: Fix ilist TreeNode string type drift

[PATCH v1] perf python: Fix ilist TreeNode string type drift

[Ian Rogers]

Updates Tree type hints to correctly use TreeNode[TreeValue]
across all assignments preventing mypy strictness mismatches.

Address some other minor stylistic issues reported by mypy, pylint and
Sashiko.

Assisted-by: Antigravity:gemini-3.1-pro
Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/python/ilist.py | 70 ++++++++++++++++++++------------------
 1 file changed, 37 insertions(+), 33 deletions(-)

diff --git a/tools/perf/python/ilist.py b/tools/perf/python/ilist.py
index 0d757ddb4795..4797818ef42e 100755
--- a/tools/perf/python/ilist.py
+++ b/tools/perf/python/ilist.py
@@ -6,7 +6,7 @@ from abc import ABC, abstractmethod
 import argparse
 from dataclasses import dataclass
 import math
-from typing import Any, Dict, Optional, Tuple
+from typing import Any, Dict, List, Optional, Set, Tuple
 import perf
 from textual import on
 from textual.app import App, ComposeResult
@@ -19,7 +19,7 @@ from textual.widgets import Button, Footer, Header, Input, Label, Sparkline, Sta
 from textual.widgets.tree import TreeNode
 
 
-def get_info(info: Dict[str, str], key: str):
+def get_info(info: Dict[str, Any], key: str):
     return (info[key] + "\n") if key in info else ""
 
 
@@ -234,7 +234,7 @@ class IListApp(App):
 
     def __init__(self, interval: float) -> None:
         self.interval = interval
-        self.evlist = None
+        self.evlist: Optional[perf.evlist] = None
         self.selected: Optional[TreeValue] = None
         self.search_results: list[TreeNode[TreeValue]] = []
         self.cur_search_result: TreeNode[TreeValue] | None = None
@@ -290,12 +290,12 @@ class IListApp(App):
             event = event.lower()
             search_label.update(f'Searching for events matching "{event}"')
 
-            tree: Tree[str] = self.query_one("#root", Tree)
+            tree: Tree[TreeValue] = self.query_one("#root", Tree)
 
-            def find_search_results(event: str, node: TreeNode[str],
+            def find_search_results(event: str, node: TreeNode[TreeValue],
                                     cursor_seen: bool = False,
-                                    match_after_cursor: Optional[TreeNode[str]] = None
-                                    ) -> Tuple[bool, Optional[TreeNode[str]]]:
+                                    match_after_cursor: Optional[TreeNode[TreeValue]] = None
+                                    ) -> Tuple[bool, Optional[TreeNode[TreeValue]]]:
                 """Find nodes that match the search remembering the one after the cursor."""
                 if not cursor_seen and node == tree.cursor_node:
                     cursor_seen = True
@@ -332,7 +332,7 @@ class IListApp(App):
 
     def action_collapse(self) -> None:
         """Collapse the part of the tree currently on."""
-        tree: Tree[str] = self.query_one("#root", Tree)
+        tree: Tree[TreeValue] = self.query_one("#root", Tree)
         node = tree.cursor_node
         if node and node.parent:
             node.parent.collapse_all()
@@ -343,31 +343,34 @@ class IListApp(App):
         if not self.selected or not self.evlist:
             return
 
-        def update_count(cpu: int, count: int):
+        def update_count(cpu: int, count: int | float):
             # Update the raw count display.
-            counter: Label = self.query(f"#counter_cpu{cpu}" if cpu >= 0 else "#counter_total")
-            if not counter:
+            counter_query = self.query(f"#counter_cpu{cpu}" if cpu >= 0 else "#counter_total")
+            if not counter_query:
                 return
-            counter = counter.first(Label)
+            counter: Label = counter_query.first(Label)
             counter.update(str(count))
 
             # Update the sparkline.
-            line: Sparkline = self.query(f"#sparkline_cpu{cpu}" if cpu >= 0 else "#sparkline_total")
-            if not line:
+            line_query = self.query(f"#sparkline_cpu{cpu}" if cpu >= 0 else "#sparkline_total")
+            if not line_query:
                 return
-            line = line.first(Sparkline)
+            line: Sparkline = line_query.first(Sparkline)
             # If there are more events than the width, remove the front event.
-            if len(line.data) > line.size.width:
-                line.data.pop(0)
-            line.data.append(count)
-            line.mutate_reactive(Sparkline.data)
+            if line.data is not None:
+                if len(line.data) > line.size.width:
+                    line.data = line.data[1:]
+                line.data = list(line.data) + [float(count)]
+            else:
+                line.data = [float(count)]
+            line.refresh()
 
         # Update the total and each CPU counts, assume there's just 1 evsel.
-        total = 0
+        total: float = 0.0
         self.evlist.disable()
         for evsel in self.evlist:
             for cpu in evsel.cpus():
-                aggr = 0
+                aggr: float = 0.0
                 for thread in evsel.threads():
                     aggr += self.selected.value(self.evlist, evsel, cpu, thread)
                 update_count(cpu, aggr)
@@ -424,16 +427,16 @@ class IListApp(App):
         # Add spark lines for all the CPUs. Note, must be done after
         # open so that the evlist CPUs have been computed by propagate
         # maps.
-        line = CounterSparkline(cpu=-1)
-        lines.mount(line)
+        line_sp = CounterSparkline(cpu=-1)
+        lines.mount(line_sp)
         for cpu in self.evlist.all_cpus():
-            line = CounterSparkline(cpu)
-            lines.mount(line)
-        line = Counter(cpu=-1)
-        lines.mount(line)
+            c_sp = CounterSparkline(cpu)
+            lines.mount(c_sp)
+        c_val = Counter(cpu=-1)
+        lines.mount(c_val)
         for cpu in self.evlist.all_cpus():
-            line = Counter(cpu)
-            lines.mount(line)
+            c_val2 = Counter(cpu)
+            lines.mount(c_val2)
 
     def compose(self) -> ComposeResult:
         """Draws the app."""
@@ -459,17 +462,18 @@ class IListApp(App):
                     # Reading events may fail with EPERM, ignore.
                     pass
             metrics = tree.root.add("Metrics")
-            groups = set()
+            groups: Set[str] = set()
             for metric in perf.metrics():
                 groups.update(metric["MetricGroup"])
 
-            def add_metrics_to_tree(node: TreeNode[TreeValue], parent: str, pmu: str = None):
+            def add_metrics_to_tree(node: TreeNode[TreeValue], parent: str, pmu: Optional[str] = None):
                 for metric in sorted(perf.metrics(), key=lambda x: x["MetricName"]):
-                    metric_pmu = metric.get('PMU')
+                    metric_pmu_raw = metric.get('PMU')
+                    metric_pmu = str(metric_pmu_raw) if metric_pmu_raw else ''
                     if pmu and metric_pmu and metric_pmu != pmu:
                         continue
                     if parent in metric["MetricGroup"]:
-                        name = metric["MetricName"]
+                        name = str(metric["MetricName"])
                         display_name = name
                         if metric_pmu:
                             display_name += f" ({metric_pmu})"
-- 
2.55.0.1007.g17ff1f9808-goog

Re: [PATCH v1] perf python: Fix ilist TreeNode string type drift

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The use of PEP 604 union type syntax `int | float` in function parameters breaks runtime compatibility with Python 3.9.
--

commit 79e3c05b8663765b4c4ea91366e2819e32834d75
Author: Ian Rogers <irogers@google.com>
Subject: perf python: Fix ilist TreeNode string type drift

This commit updates Tree type hints across the perf python ilist module to
prevent mypy strictness mismatches. It also addresses minor stylistic issues
reported by mypy, pylint, and Sashiko.

> diff --git a/tools/perf/python/ilist.py b/tools/perf/python/ilist.py
> --- a/tools/perf/python/ilist.py
> +++ b/tools/perf/python/ilist.py
[ ... ]
> @@ -343,31 +343,34 @@ class IListApp(App):
>          if not self.selected or not self.evlist:
>              return
>  
> -        def update_count(cpu: int, count: int):
> +        def update_count(cpu: int, count: int | float):

[Severity: Medium]
Does this new type hint syntax break compatibility with Python 3.9?

Evaluating the PEP 604 union type syntax int | float as a function parameter
annotation in Python 3.9 (without from __future__ import annotations) raises
a TypeError at runtime. 

Since Python 3.9 is the minimum supported version for kernel auxiliary
scripts, this will crash the perf userspace tool immediately on startup when
IListApp.on_mount() calls update_counts(), which defines the update_count
inner function.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260910174420.3002597-1-irogers@google.com?part=1

[PATCH v2] perf python: Fix ilist TreeNode string type drift

[Ian Rogers]

Updates Tree type hints to correctly use TreeNode[TreeValue]
across all assignments preventing mypy strictness mismatches.

Address some other minor stylistic issues reported by mypy, pylint and
Sashiko.

Assisted-by: Antigravity:gemini-3.1-pro
Signed-off-by: Ian Rogers <irogers@google.com>
---
v2: Tweak the imports and type annotations for better 3.9
    compatibility and to be more pythonic.
---
 tools/perf/python/ilist.py | 78 ++++++++++++++++++++------------------
 1 file changed, 42 insertions(+), 36 deletions(-)

diff --git a/tools/perf/python/ilist.py b/tools/perf/python/ilist.py
index 0d757ddb4795..ebff0a843b7a 100755
--- a/tools/perf/python/ilist.py
+++ b/tools/perf/python/ilist.py
@@ -2,11 +2,13 @@
 # SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
 """Interactive perf list."""
 
-from abc import ABC, abstractmethod
+from __future__ import annotations
+
 import argparse
+from abc import ABC, abstractmethod
 from dataclasses import dataclass
 import math
-from typing import Any, Dict, Optional, Tuple
+from typing import Any, Optional
 import perf
 from textual import on
 from textual.app import App, ComposeResult
@@ -19,7 +21,7 @@ from textual.widgets import Button, Footer, Header, Input, Label, Sparkline, Sta
 from textual.widgets.tree import TreeNode
 
 
-def get_info(info: Dict[str, str], key: str):
+def get_info(info: dict[str, Any], key: str):
     return (info[key] + "\n") if key in info else ""
 
 
@@ -140,7 +142,7 @@ class ErrorScreen(ModalScreen[bool]):
     def compose(self) -> ComposeResult:
         yield Button(f"Error: {self.error}", variant="primary", id="error")
 
-    def on_button_pressed(self, event: Button.Pressed) -> None:
+    def on_button_pressed(self) -> None:
         self.dismiss(True)
 
 
@@ -234,7 +236,7 @@ class IListApp(App):
 
     def __init__(self, interval: float) -> None:
         self.interval = interval
-        self.evlist = None
+        self.evlist: Optional[perf.evlist] = None
         self.selected: Optional[TreeValue] = None
         self.search_results: list[TreeNode[TreeValue]] = []
         self.cur_search_result: TreeNode[TreeValue] | None = None
@@ -284,18 +286,18 @@ class IListApp(App):
             """Sets the focus after the SearchScreen is dismissed."""
 
             search_label = self.query_one("#active_search", Label)
-            search_label.display = True if event else False
+            search_label.display = bool(event)
             if not event:
                 return
             event = event.lower()
             search_label.update(f'Searching for events matching "{event}"')
 
-            tree: Tree[str] = self.query_one("#root", Tree)
+            tree: Tree[TreeValue] = self.query_one("#root", Tree)
 
-            def find_search_results(event: str, node: TreeNode[str],
+            def find_search_results(event: str, node: TreeNode[TreeValue],
                                     cursor_seen: bool = False,
-                                    match_after_cursor: Optional[TreeNode[str]] = None
-                                    ) -> Tuple[bool, Optional[TreeNode[str]]]:
+                                    match_after_cursor: Optional[TreeNode[TreeValue]] = None
+                                    ) -> tuple[bool, Optional[TreeNode[TreeValue]]]:
                 """Find nodes that match the search remembering the one after the cursor."""
                 if not cursor_seen and node == tree.cursor_node:
                     cursor_seen = True
@@ -332,7 +334,7 @@ class IListApp(App):
 
     def action_collapse(self) -> None:
         """Collapse the part of the tree currently on."""
-        tree: Tree[str] = self.query_one("#root", Tree)
+        tree: Tree[TreeValue] = self.query_one("#root", Tree)
         node = tree.cursor_node
         if node and node.parent:
             node.parent.collapse_all()
@@ -343,31 +345,34 @@ class IListApp(App):
         if not self.selected or not self.evlist:
             return
 
-        def update_count(cpu: int, count: int):
+        def update_count(cpu: int, count: int | float):
             # Update the raw count display.
-            counter: Label = self.query(f"#counter_cpu{cpu}" if cpu >= 0 else "#counter_total")
-            if not counter:
+            counter_query = self.query(f"#counter_cpu{cpu}" if cpu >= 0 else "#counter_total")
+            if not counter_query:
                 return
-            counter = counter.first(Label)
+            counter: Label = counter_query.first(Label)
             counter.update(str(count))
 
             # Update the sparkline.
-            line: Sparkline = self.query(f"#sparkline_cpu{cpu}" if cpu >= 0 else "#sparkline_total")
-            if not line:
+            line_query = self.query(f"#sparkline_cpu{cpu}" if cpu >= 0 else "#sparkline_total")
+            if not line_query:
                 return
-            line = line.first(Sparkline)
+            line: Sparkline = line_query.first(Sparkline)
             # If there are more events than the width, remove the front event.
-            if len(line.data) > line.size.width:
-                line.data.pop(0)
-            line.data.append(count)
-            line.mutate_reactive(Sparkline.data)
+            if line.data is not None:
+                if len(line.data) > line.size.width:
+                    line.data = line.data[1:]
+                line.data = list(line.data) + [float(count)]
+            else:
+                line.data = [float(count)]
+            line.refresh()
 
         # Update the total and each CPU counts, assume there's just 1 evsel.
-        total = 0
+        total: float = 0.0
         self.evlist.disable()
         for evsel in self.evlist:
             for cpu in evsel.cpus():
-                aggr = 0
+                aggr: float = 0.0
                 for thread in evsel.threads():
                     aggr += self.selected.value(self.evlist, evsel, cpu, thread)
                 update_count(cpu, aggr)
@@ -424,16 +429,16 @@ class IListApp(App):
         # Add spark lines for all the CPUs. Note, must be done after
         # open so that the evlist CPUs have been computed by propagate
         # maps.
-        line = CounterSparkline(cpu=-1)
-        lines.mount(line)
+        line_sp = CounterSparkline(cpu=-1)
+        lines.mount(line_sp)
         for cpu in self.evlist.all_cpus():
-            line = CounterSparkline(cpu)
-            lines.mount(line)
-        line = Counter(cpu=-1)
-        lines.mount(line)
+            c_sp = CounterSparkline(cpu)
+            lines.mount(c_sp)
+        c_val = Counter(cpu=-1)
+        lines.mount(c_val)
         for cpu in self.evlist.all_cpus():
-            line = Counter(cpu)
-            lines.mount(line)
+            c_val2 = Counter(cpu)
+            lines.mount(c_val2)
 
     def compose(self) -> ComposeResult:
         """Draws the app."""
@@ -459,17 +464,18 @@ class IListApp(App):
                     # Reading events may fail with EPERM, ignore.
                     pass
             metrics = tree.root.add("Metrics")
-            groups = set()
+            groups: set[str] = set()
             for metric in perf.metrics():
                 groups.update(metric["MetricGroup"])
 
-            def add_metrics_to_tree(node: TreeNode[TreeValue], parent: str, pmu: str = None):
+            def add_metrics_to_tree(node: TreeNode[TreeValue], parent: str, pmu: Optional[str] = None):
                 for metric in sorted(perf.metrics(), key=lambda x: x["MetricName"]):
-                    metric_pmu = metric.get('PMU')
+                    metric_pmu_raw = metric.get('PMU')
+                    metric_pmu = str(metric_pmu_raw) if metric_pmu_raw else ''
                     if pmu and metric_pmu and metric_pmu != pmu:
                         continue
                     if parent in metric["MetricGroup"]:
-                        name = metric["MetricName"]
+                        name = str(metric["MetricName"])
                         display_name = name
                         if metric_pmu:
                             display_name += f" ({metric_pmu})"
-- 
2.55.0.1007.g17ff1f9808-goog

Re: [PATCH v2] perf python: Fix ilist TreeNode string type drift

[sashiko-bot]

> Updates Tree type hints to correctly use TreeNode[TreeValue]
> across all assignments preventing mypy strictness mismatches.
> 
> Address some other minor stylistic issues reported by mypy, pylint and
> Sashiko.
> 
> Assisted-by: Antigravity:gemini-3.1-pro
> Signed-off-by: Ian Rogers <irogers@google.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260910211539.3157204-1-irogers@google.com?part=1

Re: [PATCH v1] perf python: Fix ilist TreeNode string type drift

[Arnaldo Carvalho de Melo]

On Thu, Sep 10, 2026 at 05:51:51PM +0000, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [Medium] The use of PEP 604 union type syntax `int | float` in function parameters breaks runtime compatibility with Python 3.9.
> --

Waiting for v2,

- Arnaldo
 
> commit 79e3c05b8663765b4c4ea91366e2819e32834d75
> Author: Ian Rogers <irogers@google.com>
> Subject: perf python: Fix ilist TreeNode string type drift
> 
> This commit updates Tree type hints across the perf python ilist module to
> prevent mypy strictness mismatches. It also addresses minor stylistic issues
> reported by mypy, pylint, and Sashiko.
> 
> > diff --git a/tools/perf/python/ilist.py b/tools/perf/python/ilist.py
> > --- a/tools/perf/python/ilist.py
> > +++ b/tools/perf/python/ilist.py
> [ ... ]
> > @@ -343,31 +343,34 @@ class IListApp(App):
> >          if not self.selected or not self.evlist:
> >              return
> >  
> > -        def update_count(cpu: int, count: int):
> > +        def update_count(cpu: int, count: int | float):
> 
> [Severity: Medium]
> Does this new type hint syntax break compatibility with Python 3.9?
> 
> Evaluating the PEP 604 union type syntax int | float as a function parameter
> annotation in Python 3.9 (without from __future__ import annotations) raises
> a TypeError at runtime. 
> 
> Since Python 3.9 is the minimum supported version for kernel auxiliary
> scripts, this will crash the perf userspace tool immediately on startup when
> IListApp.on_mount() calls update_counts(), which defines the update_count
> inner function.
> 
> -- 
> Sashiko AI review · https://sashiko.dev/#/patchset/20260910174420.3002597-1-irogers@google.com?part=1

Re: [PATCH v1] perf python: Fix ilist TreeNode string type drift

[Ian Rogers]

On Sat, Sep 12, 2026 at 1:19 PM Arnaldo Carvalho de Melo
<acme@kernel.org> wrote:
>
> On Thu, Sep 10, 2026 at 05:51:51PM +0000, sashiko-bot@kernel.org wrote:
> > Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> > - [Medium] The use of PEP 604 union type syntax `int | float` in function parameters breaks runtime compatibility with Python 3.9.
> > --
>
> Waiting for v2,


Thanks, v2 is here:
https://lore.kernel.org/linux-perf-users/20260910211539.3157204-1-irogers@google.com/

Ian

> - Arnaldo
>
> > commit 79e3c05b8663765b4c4ea91366e2819e32834d75
> > Author: Ian Rogers <irogers@google.com>
> > Subject: perf python: Fix ilist TreeNode string type drift
> >
> > This commit updates Tree type hints across the perf python ilist module to
> > prevent mypy strictness mismatches. It also addresses minor stylistic issues
> > reported by mypy, pylint, and Sashiko.
> >
> > > diff --git a/tools/perf/python/ilist.py b/tools/perf/python/ilist.py
> > > --- a/tools/perf/python/ilist.py
> > > +++ b/tools/perf/python/ilist.py
> > [ ... ]
> > > @@ -343,31 +343,34 @@ class IListApp(App):
> > >          if not self.selected or not self.evlist:
> > >              return
> > >
> > > -        def update_count(cpu: int, count: int):
> > > +        def update_count(cpu: int, count: int | float):
> >
> > [Severity: Medium]
> > Does this new type hint syntax break compatibility with Python 3.9?
> >
> > Evaluating the PEP 604 union type syntax int | float as a function parameter
> > annotation in Python 3.9 (without from __future__ import annotations) raises
> > a TypeError at runtime.
> >
> > Since Python 3.9 is the minimum supported version for kernel auxiliary
> > scripts, this will crash the perf userspace tool immediately on startup when
> > IListApp.on_mount() calls update_counts(), which defines the update_count
> > inner function.
> >
> > --
> > Sashiko AI review · https://sashiko.dev/#/patchset/20260910174420.3002597-1-irogers@google.com?part=1

Re: [PATCH v2] perf python: Fix ilist TreeNode string type drift

[Arnaldo Carvalho de Melo]

On Thu, Sep 10, 2026 at 02:15:39PM -0700, Ian Rogers wrote:
> Updates Tree type hints to correctly use TreeNode[TreeValue]
> across all assignments preventing mypy strictness mismatches.
> 
> Address some other minor stylistic issues reported by mypy, pylint and
> Sashiko.

Thanks, applied to perf-tools-next, for v7.4.

- Arnaldo
 
> Assisted-by: Antigravity:gemini-3.1-pro
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
> v2: Tweak the imports and type annotations for better 3.9
>     compatibility and to be more pythonic.
> ---
>  tools/perf/python/ilist.py | 78 ++++++++++++++++++++------------------
>  1 file changed, 42 insertions(+), 36 deletions(-)
> 
> diff --git a/tools/perf/python/ilist.py b/tools/perf/python/ilist.py
> index 0d757ddb4795..ebff0a843b7a 100755
> --- a/tools/perf/python/ilist.py
> +++ b/tools/perf/python/ilist.py
> @@ -2,11 +2,13 @@
>  # SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
>  """Interactive perf list."""
>  
> -from abc import ABC, abstractmethod
> +from __future__ import annotations
> +
>  import argparse
> +from abc import ABC, abstractmethod
>  from dataclasses import dataclass
>  import math
> -from typing import Any, Dict, Optional, Tuple
> +from typing import Any, Optional
>  import perf
>  from textual import on
>  from textual.app import App, ComposeResult
> @@ -19,7 +21,7 @@ from textual.widgets import Button, Footer, Header, Input, Label, Sparkline, Sta
>  from textual.widgets.tree import TreeNode
>  
>  
> -def get_info(info: Dict[str, str], key: str):
> +def get_info(info: dict[str, Any], key: str):
>      return (info[key] + "\n") if key in info else ""
>  
>  
> @@ -140,7 +142,7 @@ class ErrorScreen(ModalScreen[bool]):
>      def compose(self) -> ComposeResult:
>          yield Button(f"Error: {self.error}", variant="primary", id="error")
>  
> -    def on_button_pressed(self, event: Button.Pressed) -> None:
> +    def on_button_pressed(self) -> None:
>          self.dismiss(True)
>  
>  
> @@ -234,7 +236,7 @@ class IListApp(App):
>  
>      def __init__(self, interval: float) -> None:
>          self.interval = interval
> -        self.evlist = None
> +        self.evlist: Optional[perf.evlist] = None
>          self.selected: Optional[TreeValue] = None
>          self.search_results: list[TreeNode[TreeValue]] = []
>          self.cur_search_result: TreeNode[TreeValue] | None = None
> @@ -284,18 +286,18 @@ class IListApp(App):
>              """Sets the focus after the SearchScreen is dismissed."""
>  
>              search_label = self.query_one("#active_search", Label)
> -            search_label.display = True if event else False
> +            search_label.display = bool(event)
>              if not event:
>                  return
>              event = event.lower()
>              search_label.update(f'Searching for events matching "{event}"')
>  
> -            tree: Tree[str] = self.query_one("#root", Tree)
> +            tree: Tree[TreeValue] = self.query_one("#root", Tree)
>  
> -            def find_search_results(event: str, node: TreeNode[str],
> +            def find_search_results(event: str, node: TreeNode[TreeValue],
>                                      cursor_seen: bool = False,
> -                                    match_after_cursor: Optional[TreeNode[str]] = None
> -                                    ) -> Tuple[bool, Optional[TreeNode[str]]]:
> +                                    match_after_cursor: Optional[TreeNode[TreeValue]] = None
> +                                    ) -> tuple[bool, Optional[TreeNode[TreeValue]]]:
>                  """Find nodes that match the search remembering the one after the cursor."""
>                  if not cursor_seen and node == tree.cursor_node:
>                      cursor_seen = True
> @@ -332,7 +334,7 @@ class IListApp(App):
>  
>      def action_collapse(self) -> None:
>          """Collapse the part of the tree currently on."""
> -        tree: Tree[str] = self.query_one("#root", Tree)
> +        tree: Tree[TreeValue] = self.query_one("#root", Tree)
>          node = tree.cursor_node
>          if node and node.parent:
>              node.parent.collapse_all()
> @@ -343,31 +345,34 @@ class IListApp(App):
>          if not self.selected or not self.evlist:
>              return
>  
> -        def update_count(cpu: int, count: int):
> +        def update_count(cpu: int, count: int | float):
>              # Update the raw count display.
> -            counter: Label = self.query(f"#counter_cpu{cpu}" if cpu >= 0 else "#counter_total")
> -            if not counter:
> +            counter_query = self.query(f"#counter_cpu{cpu}" if cpu >= 0 else "#counter_total")
> +            if not counter_query:
>                  return
> -            counter = counter.first(Label)
> +            counter: Label = counter_query.first(Label)
>              counter.update(str(count))
>  
>              # Update the sparkline.
> -            line: Sparkline = self.query(f"#sparkline_cpu{cpu}" if cpu >= 0 else "#sparkline_total")
> -            if not line:
> +            line_query = self.query(f"#sparkline_cpu{cpu}" if cpu >= 0 else "#sparkline_total")
> +            if not line_query:
>                  return
> -            line = line.first(Sparkline)
> +            line: Sparkline = line_query.first(Sparkline)
>              # If there are more events than the width, remove the front event.
> -            if len(line.data) > line.size.width:
> -                line.data.pop(0)
> -            line.data.append(count)
> -            line.mutate_reactive(Sparkline.data)
> +            if line.data is not None:
> +                if len(line.data) > line.size.width:
> +                    line.data = line.data[1:]
> +                line.data = list(line.data) + [float(count)]
> +            else:
> +                line.data = [float(count)]
> +            line.refresh()
>  
>          # Update the total and each CPU counts, assume there's just 1 evsel.
> -        total = 0
> +        total: float = 0.0
>          self.evlist.disable()
>          for evsel in self.evlist:
>              for cpu in evsel.cpus():
> -                aggr = 0
> +                aggr: float = 0.0
>                  for thread in evsel.threads():
>                      aggr += self.selected.value(self.evlist, evsel, cpu, thread)
>                  update_count(cpu, aggr)
> @@ -424,16 +429,16 @@ class IListApp(App):
>          # Add spark lines for all the CPUs. Note, must be done after
>          # open so that the evlist CPUs have been computed by propagate
>          # maps.
> -        line = CounterSparkline(cpu=-1)
> -        lines.mount(line)
> +        line_sp = CounterSparkline(cpu=-1)
> +        lines.mount(line_sp)
>          for cpu in self.evlist.all_cpus():
> -            line = CounterSparkline(cpu)
> -            lines.mount(line)
> -        line = Counter(cpu=-1)
> -        lines.mount(line)
> +            c_sp = CounterSparkline(cpu)
> +            lines.mount(c_sp)
> +        c_val = Counter(cpu=-1)
> +        lines.mount(c_val)
>          for cpu in self.evlist.all_cpus():
> -            line = Counter(cpu)
> -            lines.mount(line)
> +            c_val2 = Counter(cpu)
> +            lines.mount(c_val2)
>  
>      def compose(self) -> ComposeResult:
>          """Draws the app."""
> @@ -459,17 +464,18 @@ class IListApp(App):
>                      # Reading events may fail with EPERM, ignore.
>                      pass
>              metrics = tree.root.add("Metrics")
> -            groups = set()
> +            groups: set[str] = set()
>              for metric in perf.metrics():
>                  groups.update(metric["MetricGroup"])
>  
> -            def add_metrics_to_tree(node: TreeNode[TreeValue], parent: str, pmu: str = None):
> +            def add_metrics_to_tree(node: TreeNode[TreeValue], parent: str, pmu: Optional[str] = None):
>                  for metric in sorted(perf.metrics(), key=lambda x: x["MetricName"]):
> -                    metric_pmu = metric.get('PMU')
> +                    metric_pmu_raw = metric.get('PMU')
> +                    metric_pmu = str(metric_pmu_raw) if metric_pmu_raw else ''
>                      if pmu and metric_pmu and metric_pmu != pmu:
>                          continue
>                      if parent in metric["MetricGroup"]:
> -                        name = metric["MetricName"]
> +                        name = str(metric["MetricName"])
>                          display_name = name
>                          if metric_pmu:
>                              display_name += f" ({metric_pmu})"
> -- 
> 2.55.0.1007.g17ff1f9808-goog