> Have you seen somewhere claim that MADV_FREE allows avoiding a shootdown? I haven't, and after looking at mm/madvise.c [ https://git.kernel.org/pub/scm/linux

> Have you seen somewhere claim that MADV_FREE allows avoiding a shootdown? I haven't, and after looking at mm/madvise.c [ https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/mm/madvise.c#n700 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/lin... ] I guess it doesn't. Also, the unmapping happens immediately. MADV_DONTNEED doesn't help either, it also seems to invalidate immediately. That only leaves MADV_REMOVE, which AFAIK doesn't work on anonymous mappings... sigh [Edit: good thing I don't write allocators :D]