On Wed, Jan 15, 2014 at 02:57:36PM +0530, Viresh Kumar wrote: > Hi Again, > > I am now successful in isolating a CPU completely using CPUsets, > NO_HZ_FULL and CPU hotplug.. > > My setup and requirements for those who weren't following the > earlier mails: > > For networking machines it is required to run data plane threads on > some CPUs (i.e. one thread per CPU) and these CPUs shouldn't be > interrupted by kernel at all. > > Earlier I tried CPUSets with NO_HZ by creating two groups with > load_balancing disabled between them and manually tried to move > all tasks out to CPU0 group. But even then there were interruptions > which were continuously coming on CPU1 (which I am trying to > isolate). These were some workqueue events, some timers (like > prandom), timer overflow events (As NO_HZ_FULL pushes hrtimer > to long ahead in future, 450 seconds, rather than disabling them > completely, and these hardware timers were overflowing their > counters after 90 seconds on Samsung Exynos board).
Are you sure about that? NO_HZ_FULL shouldn't touch much hrtimers. Those are independant from the tick. Although some of them seem to rely on the softirq, but that seem to concern the tick hrtimer only. -- 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/
