On Mon, 4 Mar 2013, Will Huck wrote: > > Could you explain me why shmem has more relationship with mempolicy? It seems > that there are many codes in shmem handle mempolicy, but other components in > mm subsystem just have little. NUMA mempolicy is mostly handled in mm/mempolicy.c, which services the mbind, migrate_pages, set_mempolicy, get_mempolicy system calls: which govern how process memory is distributed across NUMA nodes. mm/shmem.c is affected because it was also found useful to specify mempolicy on the shared memory objects which may back process memory: that includes SysV SHM and POSIX shared memory and tmpfs. mm/hugetlb.c contains some mempolicy handling for hugetlbfs; fs/ramfs is kept minimal, so nothing in there. Those are the memory-based filesystems, where NUMA mempolicy is most natural. The regular filesystems could support shared mempolicy too, but that would raise more awkward design questions. Hugh -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>