a basic linked list allocator implementation without free-block merging

src/allocator.rs

@@ -7,14 +7,15 @@ use x86_64::{
     VirtAddr,
 };
 use alloc::alloc::{GlobalAlloc, Layout};
-use bump::BumpAllocator;
+use linked_list::LinkedListAllocator;
 use core::ptr::null_mut;
 
 pub const HEAP_START: usize = 0x_4444_4444_0000;
 pub const HEAP_SIZE: usize = 100 * 1024; // 100 KiB
 
 #[global_allocator]
-static ALLOCATOR: Locked<BumpAllocator> = Locked::new(BumpAllocator::new());
+static ALLOCATOR: Locked<LinkedListAllocator> =
+    Locked::new(LinkedListAllocator::new());
 /// A wrapper around spin::Mutex to permit trait implementations.
 pub struct Locked<A> {
     inner: spin::Mutex<A>,

src/allocator/linked_list.rs

@@ -101,6 +101,15 @@ impl LinkedListAllocator {
         // region suitable for allocation
         Ok(alloc_start)
     }
+
+    fn size_align(layout: Layout) -> (usize, usize) {
+        let layout = layout
+            .align_to(mem::align_of::<ListNode>())
+            .expect("adjusting alignment failed")
+            .pad_to_align();
+        let size = layout.size().max(mem::size_of::<ListNode>());
+        (size, layout.align())
+    }
 }
 struct ListNode {
     size: usize,