perf(shell): prefer GPU rendering and throttle allocator trimming

Cargo.lock

@@ -703,7 +703,7 @@ dependencies = [
 [[package]]
 name = "build_helpers"
 version = "0.14.0"
-source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.2#50ff247f14653b3d3a01affef3853a1ef5d8b349"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.3#51647bdb9ec2a59ef4e4bbb695488c1f119bb250"
 dependencies = [
  "cfg_aliases",
 ]
@@ -1108,7 +1108,7 @@ dependencies = [
 [[package]]
 name = "cosmic-config"
 version = "1.0.0"
-source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.2#50ff247f14653b3d3a01affef3853a1ef5d8b349"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.3#51647bdb9ec2a59ef4e4bbb695488c1f119bb250"
 dependencies = [
  "atomicwrites",
  "cosmic-config-derive",
@@ -1129,7 +1129,7 @@ dependencies = [
 [[package]]
 name = "cosmic-config-derive"
 version = "1.0.0"
-source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.2#50ff247f14653b3d3a01affef3853a1ef5d8b349"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.3#51647bdb9ec2a59ef4e4bbb695488c1f119bb250"
 dependencies = [
  "quote",
  "syn 2.0.119",
@@ -1198,7 +1198,7 @@ dependencies = [
 [[package]]
 name = "cosmic-theme"
 version = "1.0.0"
-source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.2#50ff247f14653b3d3a01affef3853a1ef5d8b349"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.3#51647bdb9ec2a59ef4e4bbb695488c1f119bb250"
 dependencies = [
  "almost",
  "configparser",
@@ -2945,7 +2945,7 @@ dependencies = [
 [[package]]
 name = "iced"
 version = "0.14.0"
-source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.2#50ff247f14653b3d3a01affef3853a1ef5d8b349"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.3#51647bdb9ec2a59ef4e4bbb695488c1f119bb250"
 dependencies = [
  "build_helpers",
  "dnd",
@@ -2967,7 +2967,7 @@ dependencies = [
 [[package]]
 name = "iced_accessibility"
 version = "0.1.0"
-source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.2#50ff247f14653b3d3a01affef3853a1ef5d8b349"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.3#51647bdb9ec2a59ef4e4bbb695488c1f119bb250"
 dependencies = [
  "accesskit",
  "accesskit_winit",
@@ -2976,7 +2976,7 @@ dependencies = [
 [[package]]
 name = "iced_core"
 version = "0.14.0"
-source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.2#50ff247f14653b3d3a01affef3853a1ef5d8b349"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.3#51647bdb9ec2a59ef4e4bbb695488c1f119bb250"
 dependencies = [
  "bitflags 2.13.2",
  "build_helpers",
@@ -3004,7 +3004,7 @@ dependencies = [
 [[package]]
 name = "iced_debug"
 version = "0.14.0"
-source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.2#50ff247f14653b3d3a01affef3853a1ef5d8b349"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.3#51647bdb9ec2a59ef4e4bbb695488c1f119bb250"
 dependencies = [
  "iced_core",
  "iced_futures",
@@ -3014,7 +3014,7 @@ dependencies = [
 [[package]]
 name = "iced_futures"
 version = "0.14.0"
-source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.2#50ff247f14653b3d3a01affef3853a1ef5d8b349"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.3#51647bdb9ec2a59ef4e4bbb695488c1f119bb250"
 dependencies = [
  "futures",
  "iced_core",
@@ -3028,7 +3028,7 @@ dependencies = [
 [[package]]
 name = "iced_graphics"
 version = "0.14.0"
-source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.2#50ff247f14653b3d3a01affef3853a1ef5d8b349"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.3#51647bdb9ec2a59ef4e4bbb695488c1f119bb250"
 dependencies = [
  "bitflags 2.13.2",
  "bytemuck",
@@ -3049,7 +3049,7 @@ dependencies = [
 [[package]]
 name = "iced_program"
 version = "0.14.0"
-source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.2#50ff247f14653b3d3a01affef3853a1ef5d8b349"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.3#51647bdb9ec2a59ef4e4bbb695488c1f119bb250"
 dependencies = [
  "iced_graphics",
  "iced_runtime",
@@ -3058,7 +3058,7 @@ dependencies = [
 [[package]]
 name = "iced_renderer"
 version = "0.14.0"
-source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.2#50ff247f14653b3d3a01affef3853a1ef5d8b349"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.3#51647bdb9ec2a59ef4e4bbb695488c1f119bb250"
 dependencies = [
  "iced_graphics",
  "iced_tiny_skia",
@@ -3070,7 +3070,7 @@ dependencies = [
 [[package]]
 name = "iced_runtime"
 version = "0.14.0"
-source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.2#50ff247f14653b3d3a01affef3853a1ef5d8b349"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.3#51647bdb9ec2a59ef4e4bbb695488c1f119bb250"
 dependencies = [
  "build_helpers",
  "bytes",
@@ -3087,7 +3087,7 @@ dependencies = [
 [[package]]
 name = "iced_tiny_skia"
 version = "0.14.0"
-source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.2#50ff247f14653b3d3a01affef3853a1ef5d8b349"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.3#51647bdb9ec2a59ef4e4bbb695488c1f119bb250"
 dependencies = [
  "bytemuck",
  "cosmic-text",
@@ -3104,7 +3104,7 @@ dependencies = [
 [[package]]
 name = "iced_wgpu"
 version = "0.14.0"
-source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.2#50ff247f14653b3d3a01affef3853a1ef5d8b349"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.3#51647bdb9ec2a59ef4e4bbb695488c1f119bb250"
 dependencies = [
  "as-raw-xcb-connection",
  "bitflags 2.13.2",
@@ -3136,7 +3136,7 @@ dependencies = [
 [[package]]
 name = "iced_widget"
 version = "0.14.2"
-source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.2#50ff247f14653b3d3a01affef3853a1ef5d8b349"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.3#51647bdb9ec2a59ef4e4bbb695488c1f119bb250"
 dependencies = [
  "build_helpers",
  "cosmic-client-toolkit",
@@ -3156,7 +3156,7 @@ dependencies = [
 [[package]]
 name = "iced_winit"
 version = "0.14.0"
-source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.2#50ff247f14653b3d3a01affef3853a1ef5d8b349"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.3#51647bdb9ec2a59ef4e4bbb695488c1f119bb250"
 dependencies = [
  "build_helpers",
  "cosmic-client-toolkit",
@@ -3709,7 +3709,7 @@ checksum = "3eaf3ede3fee6db1a4c2ee091bf8a8b4dccdc6d17f656fb07896ee72867612f2"
 [[package]]
 name = "libcosmic"
 version = "1.0.0"
-source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.2#50ff247f14653b3d3a01affef3853a1ef5d8b349"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.3-rc.3#51647bdb9ec2a59ef4e4bbb695488c1f119bb250"
 dependencies = [
  "apply",
  "ashpd 0.12.3",

Cargo.toml

@@ -46,8 +46,8 @@ bitflags = "2.9.4"
 calloop = { version = "0.14.5", features = ["signals"] }
 jiff = "0.2.37"
 libc = "0.2.176"
-iced_accessibility = { git = "https://github.com/ferese-wm/libcosmic", tag = "ferese-v0.1.3-rc.2" }
+iced_accessibility = { git = "https://github.com/ferese-wm/libcosmic", tag = "ferese-v0.1.3-rc.3" }
-libcosmic = { git = "https://github.com/ferese-wm/libcosmic", tag = "ferese-v0.1.3-rc.2", default-features = false, features = ["multi-window", "tokio", "wayland"] }
+libcosmic = { git = "https://github.com/ferese-wm/libcosmic", tag = "ferese-v0.1.3-rc.3", default-features = false, features = ["multi-window", "tokio", "wayland"] }
 smithay = { git = "https://github.com/Smithay/smithay", rev = "8a270232f1bfc416c781273c98a3f52a812a0bba", default-features = false, features = [
     "backend_drm",
     "backend_gbm",

scripts/tests/test_shell_motion_isolated.py

@@ -2,6 +2,7 @@
 
 FERESE_TEST_SHELL_MOTION=1 python3 scripts/tests/test_shell_motion_isolated.py
 Set FERESE_TEST_BAR_LAYOUT=floating to also test island masks and live switching.
+Set FERESE_TEST_SHELL_BACKEND=wgpu to exercise GPU rendering.
 Uses release binaries by default. Requires a Wayland host, dbus-daemon and gdbus.
 Protocol traces contain only this test's shell traffic, never the host desktop.
 """
@@ -44,6 +45,7 @@ class ShellMotionTest(unittest.TestCase):
             config = root / "config/ferese"
             config.mkdir(parents=True)
             bar_layout = os.environ.get("FERESE_TEST_BAR_LAYOUT", "flat")
+            shell_backend = os.environ.get("FERESE_TEST_SHELL_BACKEND", "tiny-skia")
             self.assertIn(bar_layout, ("flat", "floating"))
             config_file = config / "config.kdl"
             config_file.write_text(
@@ -185,7 +187,7 @@ class ShellMotionTest(unittest.TestCase):
                                  stdout=subprocess.PIPE, stderr=log, text=True)
                     env["DBUS_SESSION_BUS_ADDRESS"] = bus.stdout.readline().strip()
                     compositor = launch([str(binary), "--backend", "nested", "--grant-effects", "--grant-shell-control",
-                                         "--", "env", "WAYLAND_DEBUG=client", "ICED_BACKEND=tiny-skia", str(shell)],
+                                         "--", "env", "WAYLAND_DEBUG=client", f"ICED_BACKEND={shell_backend}", str(shell)],
                                         stdout=log, stderr=log)
                     wait_for(lambda: (ipc_socket(runtime)).is_socket())
                     wait_for(lambda: dbus("GetServerInformation", check=False).returncode == 0)

shell/ferese-shell/Cargo.toml

@@ -22,8 +22,7 @@ ferese-config = { path = "../../crates/ferese-config" }
 ferese-protocols = { path = "../../crates/ferese-protocols", default-features = false, features = ["client"] }
 jiff.workspace = true
 libc.workspace = true
-# Keep GPU rendering available as a fallback/override. The shell defaults to
+# Prefer GPU rendering, retaining software rendering as a fallback/override.
-# tiny-skia to avoid a second GPU initialization during desktop startup.
 libcosmic = { workspace = true, features = ["wgpu", "a11y"] }
 freedesktop-desktop-entry = { version = "0.8.3", default-features = false }
 iced_accessibility.workspace = true

shell/ferese-shell/src/main.rs

@@ -101,6 +101,7 @@ impl From<panel::PanelGeometry> for BarMetrics {
 }
 
 fn main() -> cosmic::iced::Result {
+    renderer::configure_shell();
     let theme_snapshot = ferese_theme_client::service::current();
     let (mut config, startup_error) = match config::load(&theme_snapshot) {
         Ok(config) => (config, None),
@@ -112,8 +113,6 @@ fn main() -> cosmic::iced::Result {
             (ShellConfig::default(), Some(notice))
         }
     };
-    renderer::configure_shell();
-
     let compositor_wallpaper = std::env::var_os("FERESE_COMPOSITOR_WALLPAPER").is_some();
     if compositor_wallpaper {
         // The compositor owns one GPU image, shared across output renderers;

shell/ferese-shell/src/renderer.rs

@@ -12,9 +12,9 @@ pub(crate) fn configure_shell() {
     APP_BACKEND.set(backend).expect("renderer configured once");
 
     if use_shell_default {
-        // Small shell surfaces do not need a second GPU device and shader setup.
+        // Prefer GPU rendering; retain software rendering for unsupported devices.
         // SAFETY: main calls this before starting any threads.
-        unsafe { std::env::set_var("ICED_BACKEND", "tiny-skia,wgpu") };
+        unsafe { std::env::set_var("ICED_BACKEND", "wgpu,tiny-skia") };
     }
 }
 
@@ -40,9 +40,60 @@ mod tests {
     use super::*;
 
     #[test]
-    fn settings_does_not_inherit_the_shells_automatic_software_renderer() {
+    fn shell_prefers_wgpu_and_preserves_explicit_renderer_choices() {
+        const CHILD: &str = "FERESE_TEST_RENDERER_CHILD";
+        if std::env::var_os(CHILD).is_some() {
+            let original = std::env::var_os("ICED_BACKEND");
+            configure_shell();
+            assert_eq!(
+                std::env::var_os("ICED_BACKEND"),
+                Some(original.clone().unwrap_or_else(|| "wgpu,tiny-skia".into()))
+            );
+            let mut app = Command::new("ferese-settings");
+            configure_app(&mut app);
+            assert_eq!(
+                app.get_envs()
+                    .find(|(key, _)| *key == "ICED_BACKEND")
+                    .unwrap()
+                    .1,
+                original.as_deref()
+            );
+            return;
+        }
+        // Each child configures its environment before the toolkit starts.
+        for backend in [
+            None,
+            Some("tiny-skia"),
+            Some("wgpu"),
+            Some("tiny-skia,wgpu"),
+        ] {
+            let mut child = Command::new(std::env::current_exe().unwrap());
+            child
+                .args([
+                    "--exact",
+                    "renderer::tests::shell_prefers_wgpu_and_preserves_explicit_renderer_choices",
+                    "--test-threads=1",
+                ])
+                .env(CHILD, "1");
+            if let Some(backend) = backend {
+                child.env("ICED_BACKEND", backend);
+            } else {
+                child.env_remove("ICED_BACKEND");
+            }
+            let output = child.output().unwrap();
+            assert!(
+                output.status.success(),
+                "backend {backend:?}:\n{}\n{}",
+                String::from_utf8_lossy(&output.stdout),
+                String::from_utf8_lossy(&output.stderr)
+            );
+        }
+    }
+
+    #[test]
+    fn settings_does_not_inherit_the_shells_automatic_renderer_preference() {
         let mut command = Command::new("ferese-settings");
-        command.env("ICED_BACKEND", "tiny-skia,wgpu");
+        command.env("ICED_BACKEND", "wgpu,tiny-skia");
         apply_app_backend(&mut command, None);
         assert_eq!(
             command