On Thu, 2017-08-24 at 18:40 +0200, Frederic Barrat wrote: > > The decrementing part is giving me troubles, and I think it makes sense: > if I decrement the counter when detaching the context from the capi > card, then the next TLBIs for the memory context may be back to local.
Yes, you need to flush the CAPI TLB first. > So when the process exits, the NPU wouldn't get the associated TLBIs, > which spells trouble the next time the same memory context ID is reused. > I believe this the cause of the problem I'm seeing. As soon as I keep > the TLBIs global, even after I detach from the capi adapter, everything > is fine. > > Does it sound right? > > So to keep the checks minimal in mm_is_thread_local(), to just checking > the active_cpus count, I'm thinking of introducing a "copro enabled" bit > on the context, so that we can increment active_cpus only once. And > never decrement it. You can decrement if you flush. Don't you have MMIOs to do directed flushes ? Cheers, Ben.
