On Wed, 2019-10-30 at 11:04 +0100, Peter Zijlstra wrote: > > You mean shatter performance? > > Shatter (all) large pages. So it looks like this is already happening then to some degree. It's not just BPF either, any module_alloc() user is going to do something similar with the direct map alias of the page they got for the text. So there must be at least some usages where breaking the direct map down, for like a page to store a key or something, isn't totally horrible.
