Script assisted by Claude

2026-08-27 12:12:58 +01:00
commit 817cac2ddc
2 changed files with 120 additions and 0 deletions
@@ -0,0 +1,118 @@
+"""
+gpu_keepalive.py
+
+Tiny AMD GPU keep-alive utility for Windows/WDDM VRAM eviction issues
+(e.g. llama.cpp / llama-server on RX 7900 XTX + Adrenalin drivers).
+
+What it does:
+  - Opens an OpenCL context on the AMD GPU
+  - Allocates a small buffer resident in GPU memory
+  - Runs a trivial kernel against it on a timer
+  - This keeps the GPU context "active" so the driver's idle
+    power-management / residency-trim path doesn't decide to
+    evict allocations to system RAM.
+
+This does NOT touch llama.cpp or llama-server directly. It just
+keeps the card from ever reaching the idle state that triggers
+eviction, so llama-server's own VRAM allocation is less likely
+to get trimmed.
+
+Requirements:
+    pip install pyopencl
+
+Usage:
+    python gpu_keepalive.py                # defaults: 4s interval, 64MB buffer
+    python gpu_keepalive.py --interval 3 --size-mb 128
+    python gpu_keepalive.py --list         # list available OpenCL devices
+
+Stop with Ctrl+C.
+"""
+
+import argparse
+import sys
+import time
+
+try:
+    import pyopencl as cl
+    import numpy as np
+except ImportError:
+    print("Missing dependencies. Install with:\n    pip install pyopencl numpy")
+    sys.exit(1)
+
+
+KERNEL_SRC = """
+__kernel void touch(__global float* buf) {
+    int i = get_global_id(0);
+    buf[i] = buf[i] + 1.0f;
+}
+"""
+
+
+def find_amd_device():
+    for platform in cl.get_platforms():
+        for device in platform.get_devices():
+            if device.type & cl.device_type.GPU and "amd" in (platform.name + device.name).lower():
+                return platform, device
+    # fallback: just grab the first GPU device found
+    for platform in cl.get_platforms():
+        for device in platform.get_devices():
+            if device.type & cl.device_type.GPU:
+                return platform, device
+    return None, None
+
+
+def list_devices():
+    for platform in cl.get_platforms():
+        print(f"Platform: {platform.name}")
+        for device in platform.get_devices():
+            print(f"  Device: {device.name}  ({device.type})")
+
+
+def main():
+    parser = argparse.ArgumentParser(description="Tiny AMD GPU keep-alive to prevent WDDM VRAM eviction.")
+    parser.add_argument("--interval", type=float, default=4.0, help="Seconds between GPU touches (default: 4)")
+    parser.add_argument("--size-mb", type=int, default=64, help="Size of the resident buffer in MB (default: 64)")
+    parser.add_argument("--list", action="store_true", help="List OpenCL platforms/devices and exit")
+    args = parser.parse_args()
+
+    if args.list:
+        list_devices()
+        return
+
+    platform, device = find_amd_device()
+    if device is None:
+        print("No OpenCL GPU device found. Is the AMD OpenCL runtime installed (it ships with Adrenalin)?")
+        sys.exit(1)
+
+    print(f"Using platform: {platform.name}")
+    print(f"Using device:   {device.name}")
+
+    ctx = cl.Context([device])
+    queue = cl.CommandQueue(ctx)
+    program = cl.Program(ctx, KERNEL_SRC).build()
+    kernel = cl.Kernel(program, "touch")
+
+    n_floats = (args.size_mb * 1024 * 1024) // 4
+    host_buf = np.zeros(n_floats, dtype=np.float32)
+    mf = cl.mem_flags
+    gpu_buf = cl.Buffer(ctx, mf.READ_WRITE | mf.COPY_HOST_PTR, hostbuf=host_buf)
+
+    print(f"Resident buffer: {args.size_mb} MB")
+    print(f"Touch interval:  {args.interval}s")
+    print("Running. Ctrl+C to stop.\n")
+
+    try:
+        tick = 0
+        while True:
+            kernel.set_args(gpu_buf)
+            cl.enqueue_nd_range_kernel(queue, kernel, (n_floats,), None)
+            queue.finish()
+            tick += 1
+            print(f"\r[keep-alive] touched GPU buffer #{tick}", end="", flush=True)
+            time.sleep(args.interval)
+    except KeyboardInterrupt:
+        print("\nStopped.")
+
+
+if __name__ == "__main__":
+    main()