Hi Ingo, Ingo Molnar wrote: > * Gregory Haskins wrote: > > >> Can I ask a simple question in light of all this discussion? >> >> "Is get_task_struct() really that bad?" >> > > it dirties a cacheline and it also involves atomics. > Yes, understood. But we should note we are always going to be talking about thrashing caches here since we are ultimately having one CPU observe another. There's no way to get around that. I understand that there are various degrees of this occurring, and I have no doubt that the proposed improvements strive to achieve a reduction of that. My question is really targeted at "at what cost". Don't get me wrong. I am not advocating going back to get/put-task per se. I am simply asking the question of whether we have taken the design off into the weeds having lost sight of the actual requirements and/or results. Its starting to smell like we have. This is just a friendly reality check. Feel free to disregard. ;) -Greg