https://github.com/Atoptool/atop/pull/345

From aae92fe43b4f3577d7bf84f347514e432071f282 Mon Sep 17 00:00:00 2001
From: "Z. Liu" <zhixu.liu@gmail.com>
Date: Thu, 24 Jul 2025 11:47:10 +0800
Subject: [PATCH 1/2] atopgpud: fork before any thread action

since python 3.12, os.fork now raise a DeprecationWarning, see
https://docs.python.org/3/whatsnew/3.12.html#deprecated:

> /usr/bin/atopgpud:283: DeprecationWarning: This process (pid=64696)
> is multi-threaded, use of fork() may lead to deadlocks in the child.

so let's fork as early as possible, before any thread action (gpulock &
"import pynvml").

Signed-off-by: Z. Liu <zhixu.liu@gmail.com>

diff --git a/atopgpud b/atopgpud
index 84517fe..4f8f0e5 100755
--- a/atopgpud
+++ b/atopgpud
@@ -66,7 +66,7 @@ cliterm = {}			# dict with one entry per client (client
 				# that still have to be received by this client
                                 # (pid of terminated process as key)
 
-gpulock = threading.Lock()	# mutex for access to gpulist/cliterm
+gpulock = None
 
 
 # =================================
@@ -275,15 +275,8 @@ def main():
         logging.error("Socket binding to port %d fails", GPUDPORT)
         sys.exit(1)
 
-    # -----------------------------
-    # release parent process
-    # (daemonize)
-    # -----------------------------
-    try:
-        if os.fork():
-            sys.exit(0)	# parent process exits; child continues...
-    except Exception:
-        logging.error("Failed to fork child")
+    global gpulock
+    gpulock = threading.Lock()	# mutex for access to gpulist/cliterm
 
     # -----------------------------
     # initialize GPU access for the
@@ -589,6 +582,16 @@ lg = logging.getLogger()		# root logger
 lg.addHandler(fh)
 lg.setLevel(loglevel)
 
+# -----------------------------
+# release parent process
+# (daemonize)
+# -----------------------------
+try:
+    if os.fork():
+        sys.exit(0)	# parent process exits; child continues...
+except Exception:
+    logging.error("Failed to fork child")
+
 # -----------------------------
 # load module pynvml
 # -----------------------------
-- 
2.45.2


From 1a226186868d806809cc8486eae46f5df28290b6 Mon Sep 17 00:00:00 2001
From: "Z. Liu" <zhixu.liu@gmail.com>
Date: Thu, 24 Jul 2025 17:31:44 +0800
Subject: [PATCH 2/2] atopgpud: don't daemonize if has arg "-f"

so we can handle it by openrc

Signed-off-by: Z. Liu <zhixu.liu@gmail.com>

diff --git a/atopgpud b/atopgpud
index 4f8f0e5..a0e9a3f 100755
--- a/atopgpud
+++ b/atopgpud
@@ -582,15 +582,16 @@ lg = logging.getLogger()		# root logger
 lg.addHandler(fh)
 lg.setLevel(loglevel)
 
-# -----------------------------
-# release parent process
-# (daemonize)
-# -----------------------------
-try:
-    if os.fork():
-        sys.exit(0)	# parent process exits; child continues...
-except Exception:
-    logging.error("Failed to fork child")
+if '-f' not in sys.argv:
+    # -----------------------------
+    # release parent process
+    # (daemonize)
+    # -----------------------------
+    try:
+        if os.fork():
+            sys.exit(0)	# parent process exits; child continues...
+    except Exception:
+        logging.error("Failed to fork child")
 
 # -----------------------------
 # load module pynvml
-- 
2.45.2