On Mon, Mar 21, 2016 at 07:10:51PM -0400, Thor Lancelot Simon wrote: > On Sun, Mar 20, 2016 at 08:19:23PM -0400, Thor Lancelot Simon wrote: > > > > I've attached the dmesg from the GENERIC kernel and the boot-time > > messages (giving both the xen dmesg and NetBSD dmesg) from the XEN3_DOM0 > > kernel. Xen kernel is 4.5 from pkgsrc; it is NOT a debug kernel. > > > > Interrupt routing seems to be the same, disk controller is on ioapic1 pin 6 > > in both cases. > > However, the Xen kernel emits: > > ioapic1 at mainbus0 apid 7 > ioapic1: can't remap to apid 7 > > Harmless?
I think it is, as it's trying to remap to the same value (AFAIK). But I don't know the x86 interrupt hardware that well. > What's particularly curious here to me is that we are seeing > twice as many interrupts as we should, in the poorly performing Xen > case. What controller is it ? maybe when running faster it's able to coalesce some interrupts ? The irq rate seems to be mostly the same in both cases, but with the number of I/O ops cut by half in the Xen case. -- Manuel Bouyer <[email protected]> NetBSD: 26 ans d'experience feront toujours la difference --
