am 1b678528: Merge "Fix invalid madvise() during concurrent alloc/dealloc of MemoryDealer"

        /* NOTE: it's VERY important to not free allocations of size 0 because

         * they're special as they don't have any record in the allocator

         * and could alias some real allocation (their offset is zero). */

        mDealer->deallocate(freedOffset);

        // keep the size to unmap in excess

        size_t pagesize = getpagesize();

            }

#endif

        }

        // This should be done after madvise(MADV_REMOVE), otherwise madvise()

        // might kick out the memory region that's allocated and/or written

        // right after the deallocation.

        mDealer->deallocate(freedOffset);

    }

}