[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] RE: [Xen-devel] [PATCH] Dont' round-robin the callback interrupt
Just to be clear. I'm only modifying the behavior of the irq being used for callback, so this should not affect pass through devices. Paul > -----Original Message----- > From: Keir Fraser > Sent: 12 July 2010 18:41 > To: Keir Fraser; Paul Durrant; xen-devel@xxxxxxxxxxxxxxxxxxx > Cc: Tim Deegan; Juergen Gross > Subject: Re: [Xen-devel] [PATCH] Dont' round-robin the callback > interrupt > > On 12/07/2010 18:17, "Keir Fraser" <keir.fraser@xxxxxxxxxxxxx> > wrote: > > >> However, that's not the motivation for this patch. In the > windows code, we > >> only bind event channels to vcpu 0 since we cannot get callback > interrupts on > >> multiple vcpus simultaneously, since the interrupt is level > sensitive. Thus > >> round-robining is wasteful in terms of kicking certain data > structures > >> between > >> caches (assuming a reasonably constant vcpu -> pcpu mapping). > > > > Surely that argument can be made for any interrupt that is set up > to > > round-robin among multiple CPUs? Obviously in the PV drivers case > the > > event-channel IRQ is probably the only significant source of > round-robin > > interrupts. But I don't see that it's special in any other way. > > Further, the correct semantics for LowestPrio delivery was > implemented by > Juergen Gross at Fujitsu for a reason. Cc'ing him. I suspect he will > say > that relaxing the delivery semantics will cause something he cares > about to > break. > > -- Keir > _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
|
![]() |
Lists.xenproject.org is hosted with RackSpace, monitoring our |