>> What I actually meant was is it OK for irq_work_queue_on() to be called locally >> (is this a sched bug/optimization(. Further if it is OK to be called, does it need >> to do behave more like irq_work_queue() i.e. call arch_irq_work_raise() or >> arch_send_call_function_single_ipi() is expected to handle sending IPI to self ! > > Right, so I'm not actually sure we started out with this requirement. > But you're not the first to run into this, see: > > lkml.kernel.org/r/CAJZ5v0gLankSuziQq25qTCyNqeOX43yD9jnJu_XXwbdyajfmKg@xxxxxxxxxxxxxx Thx for the link, very helpful. I've posted fix for ARC which uses software interrupt and is thus UP/SMP safe. > Initially I think irq_work_queue_on() was only used remotely, but I > think it makes sense to allow the current cpu, esp. since people seem to > be using it like that. > > Now the distinct difference between arch_irq_work_raise() and > arch_send_call_function_single_ipi() is that arch_irq_work_raise() > should be NMI-safe. Ok - so when I implement interrupt priorities (aka NMI for ARC), this needs to be highest. > > So on x86 it has to be extra careful about the lapic state, whereas the > regular IPI code doesn't. > > I seem to have forgotten the status of NMIs on ARC, but this is > something to make a note of. Not had a chance to go back to it since we last discussed. I've just been swamped with bug fixing like this one :-( Thx, -Vineet -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
