feat(perf): show GPU render and compute loadHEADmaster

xe exposes no busy percentage, but its DRM fdinfo carries per-engine
cycle counters. vram.sh becomes gpu.sh: the same scan also sums
drm-cycles-rcs/ccs per client and prints them with the GPU's cycle
counter, and Perf.js turns two scans into a percentage per engine.

The GPU card's headline is now the busier engine, with render (games)
and compute (local LLMs) as bars, then VRAM, temperature and fan.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 27 insertions, 3 deletions

diff --git a/desktop/modules/perf/PerfPanel.qml b/desktop/modules/perf/PerfPanel.qml
index 784284a..8ea4af6 100644
--- a/desktop/modules/perf/PerfPanel.qml
+++ b/desktop/modules/perf/PerfPanel.qml
@@ -320,13 +320,32 @@ Column {
 
     // --- GPU ----------------------------------------------------------------
 
-    // No utilisation: xe exposes no busy percentage.
+    // Busy per engine from fdinfo's cycle counters: render is games, compute
+    // local LLMs; the headline is the busier of the two.
     Card {
+        readonly property var busy: Perf.gpuRender === null && Perf.gpuCompute === null ? null
+            : Math.max(Perf.gpuRender ?? 0, Perf.gpuCompute ?? 0)
         title: "GPU · " + Perf.gpuName
-        headline: panel.deg(panel.gpuTemp.value)
-        headlineColor: panel.tone(panel.gpuTemp.value, panel.gpuTemp.warn, panel.gpuTemp.crit)
+        headline: busy === null ? "--" : Math.round(busy) + "%"
+        headlineColor: panel.tone(busy, 25, 75)
 
         Pair {
+            label: "Render"
+            value: Perf.gpuRender === null ? "--" : Math.round(Perf.gpuRender) + "%"
+        }
+        Bar {
+            frac: (Perf.gpuRender ?? 0) / 100
+            fill: panel.tone(Perf.gpuRender, 25, 75)
+        }
+        Pair {
+            label: "Compute"
+            value: Perf.gpuCompute === null ? "--" : Math.round(Perf.gpuCompute) + "%"
+        }
+        Bar {
+            frac: (Perf.gpuCompute ?? 0) / 100
+            fill: panel.tone(Perf.gpuCompute, 25, 75)
+        }
+        Pair {
             label: "VRAM"
             value: Perf.vram === null ? "--" : P.bytes(Perf.vram) + " / " + P.bytes(Perf.vramTotal)
         }
@@ -335,6 +354,11 @@ Column {
             fill: panel.tone(panel.pct(Perf.vram, Perf.vramTotal), 25, 75)
         }
         Pair {
+            label: "Temperature"
+            value: panel.deg(panel.gpuTemp.value)
+            valueColor: panel.tone(panel.gpuTemp.value, panel.gpuTemp.warn, panel.gpuTemp.crit)
+        }
+        Pair {
             label: "Fan"
             value: Perf.fan === null ? "--" : Perf.fan + " rpm"
         }