From b7cc353498407f29a4c9fbbf066c7eebfabc0cad Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?=
 <marmarek@invisiblethingslab.com>
Date: Mon, 25 May 2026 01:36:56 +0200
Subject: [PATCH] Reduce udev max children count on minimal VMs

Udev child uses between 2-5 MB each. With the default of 10, that's
significant part of memory of sys-net/sys-usb. Reduce to 2. This will
slow down startup a bit, but since those VMs have 2 vCPUs by default
anyway, not by much.

https://github.com/QubesOS/qubes-issues/issues/10886
---
 vm-systemd/setup-minimal-vm | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/vm-systemd/setup-minimal-vm b/vm-systemd/setup-minimal-vm
index ce1a625b..f4aa3166 100755
--- a/vm-systemd/setup-minimal-vm
+++ b/vm-systemd/setup-minimal-vm
@@ -42,11 +42,17 @@ disable_zram() {
     fi
 }
 
+limit_udev() {
+    udevadm control --children-max=2
+}
+
 if is_minimal_netvm; then
 	setup_minimal_netvm
+    limit_udev
     disable_zram
 fi
 
 if is_minimal_usbvm; then
+    limit_udev
     disable_zram
 fi