Update README.md

README.md

@@ -28,6 +28,23 @@ and then apply your limitation there.
 
 This is CRAP and a pain in the ass for performances, don't use it! 
 
+### NOTE On Linux Kernel and HyperThreading
+
+Apparently when you do anything more complex that just a couple of static routes
+and some NAT, hyperthreading enable on the CPU cores cause a noticeable loss in 
+performances. If your machine has HT enabled, disable it either from the BIOS
+or by software ( my rc.local example already do it!)
+
+As for the kernel, on my machine with latest Devuan ceres kernel (kernel v5.10)
+standard way too much work is delegated to the ksoftirqd kernel thread when 
+there are a lot of packets passing through the IP stack, to the point that the 
+machine load goes way too high to maintain a proper throughput. 
+
+Installing a PREEMPT RT kernel solved the issue in an excellent manner.
+
+Many other optimization can be done on the network stack, but using the proper
+kernel is a good start!
+
 ### HOT TO USE IT
 
 Soon or later (probably later. A long time later i mean!) i will write some