On Wed, Jun 06, 2007 at 04:07:01PM +0530, Balbir Singh wrote: > Dmitry Adamushko wrote: > > On 06/06/07, Srivatsa Vaddagiri <[EMAIL PROTECTED]> wrote: > >> On Wed, Jun 06, 2007 at 09:01:43AM +0200, Ingo Molnar wrote: > >> > [...] and my tree already contains the fixes for rt task's > >> > exec_start. > >> > >> Can I have this snapshot pls? I have to deal with the same issue when > >> the current task switches groups and I was planning to fix it by > >> introducing a set_curr_task() method in fair_sched_class which > >> initializes exec_start and other fields for that task. > > > > Hum.. what about accounting 'exec_time' and updating 'exec_start' in > > rt_sched :: dequeue_task_rt() instead (like update_curr() does it in > > dequeue_task_fair())?
[For some reason Dimitry's mail has not made it to my inbox yet ..] > > This way, on RT -> NORMAL transition.. some 'delta_exec' ( between > > deactivate_task() ---> activate_task() ) will be accounted later as if > > the task was 'sched_fair_class' during this time.. which I think makes > > some sense. What do you think? > > > > Why not do it explicitly in __setscheduler() if the new policy is SCHED_NORMAL > or SCHED_BATCH. Yes this is the approach I prefer, because we burden the fast/normal path less that way (RT->NORMAL transition is not common). That's why I was considering a set_curr_task() method in fair_sched_class which will be invoked in __setscheduler() if the new policy of currently running task happens to be SCHED_NORMAL/BATCH. Alternately if the new policy of currently running task happens to be SCHED_FIFO (and its old policy was SCHED_NORMAL) we need to invoke put_prev_task() method (so that fair_clock etc is updated based on outgoing task's execution time in SCHED_NORMAL class). >You could also add the smarts to deactivate_task() -- Regards, vatsa - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
