diff --git a/pb_utils/README.md b/pb_utils/README.md
index d25ee35a690583b470677403f2c4108955b3835b..2090bc6e881aa3e8ea7c7cc8119344240a964dc1 100644
--- a/pb_utils/README.md
+++ b/pb_utils/README.md
@@ -20,7 +20,11 @@ cd /mnt
 ./build_kernel.sh
 ```
 
-## chroot into debian rootfs to build test modules
+## ~~chroot into debian rootfs to build test modules~~
+> This is historical information, please note that this uses kernel threads.
+> Our perf events are currently configured not to count kernel space.
+> **This and possibly other changes cause this not to work**. We are using pb_submitter for testing.
+
 run `./chroot_image.sh`, this drops you in a shell on the created debian and run
 
 ```bash