Checkpointing processes with large number of small virtual memory areas (VMAs) can lead to significant performance overhead. This overhead is primarily due to the frequent reading of VMA information from <code>/proc/[pid]/pagemap</code>, as described in [[Memory dumps]]. To mitigate this problem, CRIU uses a pagemap cache (pmc) to reduce the frequency of <code>pread</code> calls by caching information about VMAs.