On Mon, Jul 30, 2018 at 12:15 PM, Rik van Riel <r...@surriel.com> wrote: > On Mon, 2018-07-30 at 18:26 +0200, Peter Zijlstra wrote: >> On Mon, Jul 30, 2018 at 10:30:11AM -0400, Rik van Riel wrote: >> >> > > What happened to the rework I did there? That not only avoided >> > > fiddling >> > > with active_mm, but also avoids grab/drop cycles for the other >> > > architectures when doing task->kthread->kthread->task things. >> > >> > I don't think I saw that. I only saw your email from >> > July 20th with this fragment of code, which does not >> > appear to avoid the grab/drop cycles, and still fiddles >> > with active_mm: >> >> Yeah, that's it. Note how it doesn't do a grab+drop for kernel- >> >kernel, >> where the current could would have. >> >> And also note that it only fiddles with active_mm if it does the >> grab+drop thing (the below should have s/ifdef/ifndef/ to make more >> sense maybe). > > I'll kick off a test with your variant. I don't think we > will see any performance difference on x86 (due to not > using a refcount at all any more), but unless Ingo is in > a hurry I guess there's no issue rewriting this part of > the patch series :) > > Do the other patches look ok to you and Andy? >
The whole series other than the active_mm stuff looked okay to me.
