On Wed, 8 Nov 2017, Yisheng Xie wrote: > Another case is current process is *not* the same as target process, and > when current process try to migrate pages of target process from old_nodes > to new_nodes, the new_nodes should be a subset of target process cpuset.
The caller of migrate_pages should be able to migrate the target process pages anywhere the caller can allocate memory. If that is outside the target processes cpuset then that is fine. Pagecache pages that are not allocated by the target process already are not subject to the target processes restriction. So this is not that unusual.
