* Avi Kivity <avi@xxxxxxxxxx> wrote: > > Defrag is not futile in theory, you just have to either have a reserve of > > movable pages (and never allow pinned kernel pages in there), or you need > > to allocate pinned kernel memory in units of the chunk size goal (which > > just gives you different types of fragmentation problems) or you need to > > do non-linear kernel mappings so you can defrag pinned kernel memory (with > > *lots* of other problems of course). So you just have a lot of downsides. > > Non-linear kernel mapping moves the small page problem from userspace back > to the kernel, a really unhappy solution. Note that in a theoretical sense a specific variant of non-linear kernel mappings is already implemented here and toda and is productized: it's called virtualization. Ingo -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>