organize

services/llama-cpp/llama-cpp-xmrig-pause.py

@@ -0,0 +1,123 @@
+#!/usr/bin/env python3
+"""
+Pause xmrig while llama-cpp is processing inference requests.
+
+Checks if the llama-server process is actively using CPU by reading
+/proc/<pid>/stat. When CPU usage exceeds the threshold, stops xmrig.
+When CPU drops below threshold for GRACE_PERIOD seconds, restarts xmrig.
+"""
+
+import glob
+import os
+import subprocess
+import sys
+import time
+
+POLL_INTERVAL = int(os.environ.get("POLL_INTERVAL", "3"))
+GRACE_PERIOD = float(os.environ.get("GRACE_PERIOD", "10"))
+# CPU percentage (per-core) above which llama-server is considered busy.
+# Idle llama-server uses ~0% CPU; active inference saturates multiple cores.
+CPU_THRESHOLD = float(os.environ.get("CPU_THRESHOLD", "50"))
+
+
+def log(msg):
+    print(f"[llama-cpp-xmrig-pause] {msg}", file=sys.stderr, flush=True)
+
+
+def find_llama_pid():
+    """Find the PID of the llama-server process."""
+    for path in glob.glob("/proc/[0-9]*/comm"):
+        try:
+            with open(path) as f:
+                if f.read().strip() == "llama-server":
+                    return int(path.split("/")[2])
+        except (OSError, ValueError):
+            continue
+    return None
+
+
+def get_cpu_times(pid):
+    """Read utime + stime from /proc/<pid>/stat. Returns total ticks or None."""
+    try:
+        with open(f"/proc/{pid}/stat") as f:
+            fields = f.read().split(")")[-1].split()
+            # fields[11] = utime, fields[12] = stime (0-indexed after ')')
+            return int(fields[11]) + int(fields[12])
+    except (OSError, IndexError, ValueError):
+        return None
+
+
+def systemctl(action, unit):
+    result = subprocess.run(
+        ["systemctl", action, unit],
+        capture_output=True,
+        text=True,
+    )
+    if result.returncode != 0:
+        log(f"systemctl {action} {unit} failed (rc={result.returncode}): {result.stderr.strip()}")
+    return result.returncode == 0
+
+
+def main():
+    xmrig_paused = False
+    idle_since = None
+    prev_ticks = None
+    prev_time = None
+    hz = os.sysconf("SC_CLK_TCK")
+
+    log(f"Starting: poll={POLL_INTERVAL}s grace={GRACE_PERIOD}s threshold={CPU_THRESHOLD}%")
+
+    while True:
+        pid = find_llama_pid()
+        if pid is None:
+            # llama-server not running
+            idle_since = None
+            prev_ticks = None
+            prev_time = None
+            time.sleep(POLL_INTERVAL)
+            continue
+
+        ticks = get_cpu_times(pid)
+        now = time.monotonic()
+
+        if ticks is None or prev_ticks is None or prev_time is None:
+            prev_ticks = ticks
+            prev_time = now
+            time.sleep(POLL_INTERVAL)
+            continue
+
+        dt = now - prev_time
+        if dt <= 0:
+            prev_ticks = ticks
+            prev_time = now
+            time.sleep(POLL_INTERVAL)
+            continue
+
+        # CPU% = (delta_ticks / hz) / delta_seconds * 100
+        cpu_pct = ((ticks - prev_ticks) / hz) / dt * 100
+        prev_ticks = ticks
+        prev_time = now
+
+        busy = cpu_pct > CPU_THRESHOLD
+
+        if busy:
+            idle_since = None
+            if not xmrig_paused:
+                log(f"llama-server busy ({cpu_pct:.0f}% CPU) — stopping xmrig")
+                if systemctl("stop", "xmrig"):
+                    xmrig_paused = True
+        else:
+            if xmrig_paused:
+                if idle_since is None:
+                    idle_since = now
+                elif now - idle_since >= GRACE_PERIOD:
+                    log(f"llama-server idle ({cpu_pct:.0f}% CPU) past grace period — starting xmrig")
+                    if systemctl("start", "xmrig"):
+                        xmrig_paused = False
+                    idle_since = None
+
+        time.sleep(POLL_INTERVAL)
+
+
+if __name__ == "__main__":
+    main()