Hi all, I'm a user-space developer and I want to use memfd to share some memory between parent and child processes. For the demo, it works well. However, I fount that the RSS of the process using memfd will grow up faster than that using anonymous mappings. Dig some memfd/shmem code and I find that memfd/shmem will allocate a page for a read page fault. For my use case, the process may allocate tens or even hundreds of GiB memory using memfd. So allocating all memory just because of reading it will has a great impact. Could memfd/shmem map to the global zero page instead of allocating a page for a read page fault? Thanks, Peng
