Minor comment fixes

src/util/conversions.rs

@@ -94,9 +94,8 @@ pub fn bytes_to_formatted_string(bytes: usize) -> String {
     format!("{}{}", num, UNITS.last().unwrap())
 }
 
-/// Shift `num` by `bits` to the right.  Add 1 to the result if any bits are shifted out to the
-/// right.  This is equivalent to dividing `num` by 2 to the power of `bits`, rounding towards
-/// infinity.
+/// Shift `num` by `bits` to the right.  Add 1 to the result if any `1` bits are shifted out to the
+/// right.  This is equivalent to dividing `num` by 2 to the power of `bits`, rounding up.
 ///
 /// This function has undefined behavior if `bits` is greater or equal to the number of bits in
 /// `usize`.

src/util/metadata/side_metadata/global.rs

@@ -1363,7 +1363,7 @@ impl SideMetadataContext {
         let mut total = 0;
         for spec in self.global.iter() {
             // This rounds up.  No matter how small `data_pages` is, the side metadata size will be
-            // at least one page.  This behavior is *intended*.  The over-estimated amount is used
+            // at least one page.  This behavior is *intended*.  This over-estimated amount is used
             // for triggering GC and resizing the heap.
             total += data_to_meta_size_round_up(spec, data_pages);
         }