diff --git a/kernel-rs/src/memory/area_frame_allocator.rs b/kernel-rs/src/memory/area_frame_allocator.rs
index 123aa879..3693f45d 100644
--- a/kernel-rs/src/memory/area_frame_allocator.rs
+++ b/kernel-rs/src/memory/area_frame_allocator.rs
@@ -34,6 +34,8 @@ impl AreaFrameAllocator {
 
     fn choose_next_area(&mut self) {
         self.current_area = self.areas.clone().filter(|area| {
+            // filter in areas with remaining free frames
+            // i.e. next_free_frame is before the last frame
             let address = area.base_addr + area.length - 1;
             Frame::containing_address(address as usize) >= self.next_free_frame
         }).min_by_key(|area| area.base_addr);
diff --git a/kernel-rs/src/memory/mod.rs b/kernel-rs/src/memory/mod.rs
index a1358219..8cd88e6e 100644
--- a/kernel-rs/src/memory/mod.rs
+++ b/kernel-rs/src/memory/mod.rs
@@ -11,7 +11,6 @@ pub struct Frame {
 
 pub const PAGE_SIZE: usize = 4096;
 
-
 impl Frame {
     fn containing_address(address: usize) -> Frame {
         Frame{ number: address / PAGE_SIZE }