On Thu, Oct 01, 2020 at 06:49:36AM -0700, Dave Hansen wrote: > On 9/30/20 10:30 AM, Peter Zijlstra wrote: > > In general though; I think using ->active_mm is a mistake though. That > > code should be doing something like: > > > > > > mm = current->mm; > > if (!mm) > > mm = &init_mm; > > > > I was hoping that using ->active_mm would give us the *actual* copy of > the page tables that's loaded in CR3 for kernel thraeds. But, there are > few if any practical advantages of doing that at the moment.
Some of us hate active_mm with a passion and want to remove it entirely (/me waves at amluto). Also, if !current->mm, it had better not be accessing anything outside of the kernel map, so &init_mm should cover that just fine. And given the kernel maps are shared between all CR3s, they'll see the exact same pagetables.
