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, 46 insertions, 0 deletions

diff --git a/desktop/modules/perf/test_gpu.sh b/desktop/modules/perf/test_gpu.sh
new file mode 100755
index 0000000..8467c74
--- /dev/null
+++ b/desktop/modules/perf/test_gpu.sh
@@ -0,0 +1,46 @@
+#!/bin/sh
+#
+# Copyright (C) 2026 Danilo M. <danix@danix.xyz>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+
+# gpu.sh: VRAM and engine cycles summed once per xe client id, units
+# honoured, other drivers ignored; nothing at all when no xe client is found.
+set -e
+dir=$(dirname "$0")
+tmp=$(mktemp)
+trap 'rm -f "$tmp"' EXIT
+
+printf '%s\n' \
+    "/proc/1/fdinfo/7:drm-driver:	xe" \
+    "/proc/1/fdinfo/7:drm-client-id:	38" \
+    "/proc/1/fdinfo/7:drm-resident-vram0:	1024 KiB" \
+    "/proc/1/fdinfo/7:drm-cycles-rcs:	30" \
+    "/proc/1/fdinfo/7:drm-total-cycles-rcs:	1000" \
+    "/proc/1/fdinfo/10:drm-driver:	xe" \
+    "/proc/1/fdinfo/10:drm-client-id:	38" \
+    "/proc/1/fdinfo/10:drm-resident-vram0:	1024 KiB" \
+    "/proc/1/fdinfo/10:drm-cycles-rcs:	30" \
+    "/proc/1/fdinfo/10:drm-total-cycles-rcs:	1000" \
+    "/proc/2/fdinfo/5:drm-driver:	xe" \
+    "/proc/2/fdinfo/5:drm-client-id:	40" \
+    "/proc/2/fdinfo/5:drm-resident-vram0:	2 MiB" \
+    "/proc/2/fdinfo/5:drm-cycles-ccs:	7" \
+    "/proc/2/fdinfo/5:drm-total-cycles-ccs:	900" \
+    "/proc/3/fdinfo/4:drm-driver:	amdgpu" \
+    "/proc/3/fdinfo/4:drm-client-id:	1" \
+    "/proc/3/fdinfo/4:drm-resident-vram0:	9 GiB" > "$tmp"
+got=$(sh "$dir/gpu.sh" "$tmp")
+[ "$got" = "$((1024 * 1024 + 2 * 1024 * 1024)) 30 1000 7 900" ] || { echo "gpu: got '$got'"; exit 1; }
+
+: > "$tmp"
+got=$(sh "$dir/gpu.sh" "$tmp")
+[ -z "$got" ] || { echo "empty: got '$got'"; exit 1; }
+echo ok