diff --git a/sys/amd64/conf/NOTES b/sys/amd64/conf/NOTES
index 7b35fa7e5c58..c059c8049bcc 100644
--- a/sys/amd64/conf/NOTES
+++ b/sys/amd64/conf/NOTES
@@ -74,6 +74,7 @@ cpu		HAMMER			# aka K8, aka Opteron & Athlon64
 # accurate scheduling of the CPU time between kernel network processing
 # and other activities.  The drawback is a moderate (up to 1/HZ seconds)
 # potential increase in response times.
+# DEVICE_POLLING does not work with SMP.
 # It is strongly recommended to use HZ=1000 or 2000 with DEVICE_POLLING
 # to achieve smoother behaviour.
 # Additionally, you can enable/disable polling at runtime with the
diff --git a/sys/i386/conf/NOTES b/sys/i386/conf/NOTES
index ba9a5633cf18..54acb14c3f41 100644
--- a/sys/i386/conf/NOTES
+++ b/sys/i386/conf/NOTES
@@ -236,6 +236,7 @@ options 	PERFMON
 # potential increase in response times.
 # It is strongly recommended to use HZ=1000 or 2000 with DEVICE_POLLING
 # to achieve smoother behaviour.
+# DEVICE_POLLING does not work with SMP.
 # Additionally, you can enable/disable polling at runtime with the
 # sysctl variable kern.polling.enable (defaults off), and select
 # the CPU fraction reserved to userland with the sysctl variable
diff --git a/sys/pc98/conf/NOTES b/sys/pc98/conf/NOTES
index 6bf5ac343bd7..1cb172510d8d 100644
--- a/sys/pc98/conf/NOTES
+++ b/sys/pc98/conf/NOTES
@@ -196,6 +196,7 @@ options 	PERFMON
 # potential increase in response times.
 # It is strongly recommended to use HZ=1000 or 2000 with DEVICE_POLLING
 # to achieve smoother behaviour.
+# DEVICE_POLLING does not work with SMP.
 # Additionally, you can enable/disable polling at runtime with the
 # sysctl variable kern.polling.enable (defaults off), and select
 # the CPU fraction reserved to userland with the sysctl variable