The kernel's "direct map" makes the entirety of a system's physical memory available in the kernel's virtual address space. Normally, huge pages are used for this mapping, making it relatively efficient to access. Increasingly, though, there is a need to carve some pages out of the direct map; this splits up those huge pages and makes the system as a whole less efficient. During a memory-management session at the 2022 Linux Storage, Filesystem, Memory-management and BPF Summit (LSFMM), Mike Rapoport led a session on direct-map fragmentation and how it might be avoided.