assert_eq!(freed, 0);

            if freed > 0 {
                let b = if is_dirty { 1 } else { 0 };
                freed_[0] = freed | b;
            }

            assert_eq!(freed, 0);

            if freed > 0 {
                let b = if is_dirty { 1 } else { 0 };
                freed_[0] = freed | b;
            }

            assert_eq!(freed, 0);

            if freed > 0 {
                let b = if is_dirty { 1 } else { 0 };
                // index 0 is ok here: if a page is freed, it means we
                // just compacted a page, which implies that the call
                // to `put` above didn't free.
                freed_[0] = freed | b
            }

            assert_eq!(freed, 0);

            if freed > 0 {
                let b = if is_dirty { 1 } else { 0 };
                // index 0 is ok here: if we freed a page in the call
                // to `del` above, it is mutable and we can allocate
                // on it. Else, we just compacted a page, but that
                // also means `del` above didn't free.
                freed_[0] = freed | b
            }

                debug!("freed {:?} {:?}", line!(), freed);