On Mon, Aug 13, 2012 at 01:31:36PM +0300, Avi Kivity wrote: > On 08/13/2012 01:24 PM, Gleb Natapov wrote: > > On Mon, Aug 13, 2012 at 01:21:33PM +0300, Avi Kivity wrote: > >> On 08/13/2012 01:16 PM, Gleb Natapov wrote: > >> > On Mon, Aug 13, 2012 at 01:12:46PM +0300, Michael S. Tsirkin wrote: > >> >> On Mon, Aug 13, 2012 at 12:36:41PM +0300, Avi Kivity wrote: > >> >> > On 08/13/2012 12:16 PM, Gleb Natapov wrote: > >> >> > > Here is a quick prototype of what we discussed yesterday. This one > >> >> > > caches only MSI interrupts for now. The obvious problem is that not > >> >> > > all interrupts (namely IPIs and MSIs using KVM_CAP_SIGNAL_MSI) use irq > >> >> > > routing table, so they cannot be cached. > >> >> > > >> >> > We can have a small rcu-managed hash table to look those up. > >> >> > >> >> Yes but how small? We probably need at least one entry > >> >> per vcpu, no? > >> >> > >> > One entry? We will spend more time managing it than injecting interrupts > >> > :) ideally we need entry for each IPI sent and for each potential MSI > >> > from userspace. What happens when hash table is full? > >> > >> Drop the entire cache. > >> > > OK. Then it should be big enough to not do it frequently. > > Should be sized N * vcpus, where N is several dozen (generous amount of > non-device vectors, though multicast will break it since it's > essentially random). > We can even grow it at runtime if it fills out frequently. -- Gleb. -- 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
