On Tue, Oct 08, 2013 at 09:21:14AM +0200, Ingo Molnar wrote: > > * Christoph Lameter <[email protected]> wrote: > > > SNMP stats are not protected by preemption but by bh handling. > > Most forms of bh exclusion work via the preemption count though, and > softirq contexts themselves are generally not preemptible [to other CPUs] > either. > > So the warnings should, in most cases, not trigger.
Right, so softirqs run either in the irq tail at which point preempt_count += SOFTIRQ_OFFSET and thus preemption is disabled, or it runs in ksoftirqd which has strict cpu affinity which also disables the warning, and it also increments preempt_count with SOFTIRQ_OFFSET to exclude the softirq from interrupts while its running, also disabling the warning. So it should very much not trigger.. if it does you want to know about it. -- 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/
