On 2012-06-04 15:07, Thomas Gleixner wrote: > On Mon, 4 Jun 2012, Jan Kiszka wrote: >> On 2012-06-04 13:21, Thomas Gleixner wrote: >> So this shortcut requires some checks before being applied to a specific >> MSI/MSI-X vector. >> >> >> Taking KVM aside, my general question remains if threaded MSI handlers >> of all devices really need to apply IRQF_ONESHOT though they should have >> no use for it. > > In theory no, but we had more than one incident, where threaded irqs > w/o a primary handler and w/o IRQF_ONEHSOT lead to full system > starvation. Linus requested this sanity check and I think it's sane > and required. OK. > > In fact it's a non issue for MSI. MSI uses handle_edge_irq which does > not mask the interrupt. IRQF_ONESHOT is a noop for that flow handler. Isn't irq_finalize_oneshot processes for all flows? Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
