On Wed, Apr 10, 2019 at 10:18:10PM +0800, Aubrey Li wrote: > On Wed, Apr 10, 2019 at 12:36 PM Aaron Lu <aaron...@linux.alibaba.com> wrote: > > > > On Tue, Apr 09, 2019 at 11:09:45AM -0700, Tim Chen wrote: > > > Now that we have accumulated quite a number of different fixes to your > > > orginal > > > posted patches. Would you like to post a v2 of the core scheduler with > > > the fixes? > > > > One more question I'm not sure: should a task with cookie=0, i.e. tasks > > that are untagged, be allowed to scheduled on the the same core with > > another tagged task? > > > > The current patch seems to disagree on this, e.g. in pick_task(), > > if max is already chosen but max->core_cookie == 0, then we didn't care > > about cookie and simply use class_pick for the other cpu. This means we > > could schedule two tasks with different cookies(one is zero and the > > other can be tagged). > > > > But then sched_core_find() only allow idle task to match with any tagged > > tasks(we didn't place untagged tasks to the core tree of course :-). > > > > Thoughts? Do I understand this correctly? If so, I think we probably > > want to make this clear before v2. I personally feel, we shouldn't allow > > untagged tasks(like kernel threads) to match with tagged tasks. > > Does it make sense if we take untagged tasks as hypervisor, and different > cookie tasks as different VMs? Isolation is done between VMs, not between > VM and hypervisor. > > Did you see anything harmful if an untagged task and a tagged task > run simultaneously on the same core?
VM can see hypervisor's data then, I think. We probably do not want that happen.
