Quoting Daniel Vetter (2019-11-08 21:13:13) > On Fri, Nov 8, 2019 at 9:49 PM Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: > > > > One of the hardest priority inversion tasks to both handle and to > > simulate in testing is inversion due to resource contention. The > > challenge is that a high priority context should never be blocked by a > > low priority context, even if both are starving for resources -- > > ideally, at least for some RT OSes, the higher priority context has > > first pick of the meagre resources so that it can be executed with > > minimum latency. > > > > userfaultfd allows us to handle a page fault in userspace, and so > > arbitrary impose a delay on the fault handler, creating a situation > > where a low priority context is blocked waiting for the fault. This > > blocked context should not prevent a high priority context from being > > executed. While the userfault tries to emulate a slow fault (e.g. from a > > failing swap device), it is unfortunately limited to a single object > > type: the userptr. Hopefully, we will find other ways to impose other > > starvation conditions on global resources. > > > > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> > > Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> > > So rt-ww_mutexes? > > I don't think we want/should do that on the first round of rolling out > ww_mutex in i915. It works today. And will continue working across any conversion. -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
