Explain STORE_BUFFER_LIMIT of 128

Author: cbeuw

src/weak_memory.rs

@@ -68,6 +68,10 @@ use crate::{
 
 pub type AllocExtra = StoreBufferAlloc;
 
+// Each store buffer must be bounded otherwise it will grow indefinitely.
+// However, bounding the store buffer means restricting the amount of weak
+// behaviours observable. The author picked 128 as a good tradeoff
+// so we follow them here.
 const STORE_BUFFER_LIMIT: usize = 128;
 
 #[derive(Debug, Clone)]