Missed lists earlier :(
On 7 January 2014 20:31, Viresh Kumar <[email protected]> wrote: > Hi Kevin/Frederic, > > In my traces I see a guaranteed interrupt on the isolated > core, which is running under NO_HZ_FULL mode and is > running a single thread "stress", after ~90 seconds. > > When I look into the traces I see we get only two events: > - irq-handler-entry > - irq-handler-exit > > And no more detail is available in the traces, system again > goes to no interruption mode for next 90 seconds. > > I hope this is because the timers we have queued for long > enough times are getting overflowed? I tried to enable > cpusets and then see which timers are active on CPU1 from > /proc/timer_list and that gave me: > > tick_sched_timer and it_real_fn. These are probably queued > for long enough times, around 450 seconds and 2000 seconds. > > So, my question is: Why are these getting queued? And how > can I get rid of those for my case, where I want zero interruption > on isolated core, as that would be running a userspace thread > to handle data plane packets. > > > Another thing I tried out recently was to make my single threaded > task "stress" a real time task with priority 99 (along with cpusets). > But it seems there are more than one thread getting on that CPU > and so tick occurs immediately. > > I tried to call "stress" with help of chrt. > > -- > viresh -- 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/
