Mark Hounschell wrote: > Oleg Nesterov wrote: >> On 06/02, Mark Hounschell wrote: >>> Jun 2 16:36:11 harley kernel: ERR!! events/1 flush hang: c201dbc0 >>> c201dbc0 10012 10012 >>> Jun 2 16:36:11 harley kernel: CURR: 7974 7974 vrsx 93 26 >>> Jun 2 16:36:11 harley kernel: wq_barrier_func+0x0/0x8 >>> Jun 2 16:36:11 harley kernel: vmstat_update+0x0/0x24 >>> Jun 2 16:36:11 harley kernel: ---- >>> Jun 2 16:36:11 harley kernel: cache_reap+0x0/0xf4 >> As expected. >> >> Note that ->nivcsw/->nvcsw doesn't change. There is no "spare time" >> on CPU 1, "vrsx" monopolizes CPU. events/1->cache_reap() was preempted >> by vrsx, it had no chance to run since then. Note that jobs == 7974 >> doesn't change too. I forgot to print cwq->thread->state, but it should >> be TASK_RUNNING. It would not be possible to kill vrsx if cache_reap() >> stalled. >> >> I don't think this is a kernel problem, vrsx breaks flush_workqueue(). >> Ingo can answer authoritatively, but I think SCHED_RR/SCHED_FIFO were >> not designed to be 100% cpu-bound. >> >> That said, I think it makes sense to get rid of flush_scheduled_work() >> in floppy.c. >> > > Oleg, thanks for your time in diagnosing this. > > As far as a 100% CPU bound task being a valid thing to do, it has been > done for many years on SMP machines. Any kernel limitation on this > surely must be considered a bug? >
Could someone authoritatively comment on this? Is a SCHED_RR/SCHED_FIFO 100% Cpu bound process supported in an SMP env on Linux? (vanilla or -rt) Thanks and Regards Mark - 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/
