tab_title_template: Add a field that evaluated to the total memory used by all child processes in the tab

Fixes #10293

docs/changelog.rst

@@ -195,6 +195,8 @@ Detailed list of changes
 
 - Add support for `terminal visibility reports <https://rockorager.dev/misc/visibility-reports/>`__
 
+- :opt:`tab_title_template`: Add a field that evaluated to the total memory used by all child processes in the tab (:iss:`10293`)
+
 
 0.48.1 [2026-07-24]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

kitty/child.py

@@ -703,7 +703,7 @@ class Child:
             except OSError:
                 pass
 
-    def get_memory_used_by_child(self, check_if_cgroup_root: bool = False) -> int:
+    def get_memory_used_by_child(self) -> int:
         if self.pid is None:
             return -1
-        return memory_used_by_process_tree_rooted_at(self.pid, check_if_cgroup_root)
+        return memory_used_by_process_tree_rooted_at(self.pid, check_if_cgroup_root=False)

kitty/options/definition.py

@@ -2258,6 +2258,8 @@ use :code:`{sup.index}`. All data available is:
 :code:`tab.progress_percent`
     If a command running in a window reports the progress for a task, show this progress as a percentage
     from all windows in the tab, averaged. Empty string is no progress is reported.
+:code:`tab.children_mem_usage`
+    The current memory usage of all child process of the tab and their descendants
 :code:`custom`
     This will call a function named :code:`draw_title(data)` from the file :file:`tab_bar.py` placed in
     the kitty config directory. The function will be passed a dictionary of data, the same data that

kitty/tab_bar.py

@@ -285,6 +285,20 @@ class TabAccessor:
         p = int(tab.total_progress / tab.num_of_windows_with_progress)
         return f'{p}% '
 
+    @property
+    def children_mem_usage(self) -> str:
+        from kittens.tui.utils import human_size
+
+        tab = get_boss().tab_for_id(self.tab_id)
+        if not tab:
+            return ''
+        ans = 0
+        for w in tab:
+            if (m := w.child.get_memory_used_by_child()) > 0:
+                ans += m
+
+        return human_size(ans, max_num_of_decimals=0)
+
 
 safe_builtins = {
     'max': max,