On Thu, 17 Oct 2013, Frederic Weisbecker wrote: > > - /* We can run anywhere, unlike our parent keventd(). */ > > - set_cpus_allowed_ptr(current, cpu_all_mask); > > + /* We can run anywhere kthreadd can run */ > > + set_kthreadd_affinity(); > > If you really want your isolated CPUs to be undisturbed, you need this > affinity to > be set before the creation of this usermode helper. Otherwise it's going to > run to any random > place before you call the above function. > > Is there now way to control the kworker affinity which create this usermode > helpers threads > instead?
The invocation is coming from keventd so the affinity seems to be set to a different cpu before we get the thread moved. A tsc loop is running on the processor that gets hit by the usermodehelper spawns. We see spawning by the tty notifier (when typing on a vt) as well as by a mellanox driver (periodically). -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
