On Sun, Jun 19, 2011 at 03:35:58PM +0300, Avi Kivity wrote: > On 06/15/2011 12:09 PM, Gleb Natapov wrote: > >> > >> Actually, I'd expect most read/writes to benefit from caching, no? > >> So why don't we just rename kvm_write_guest_cached() to > >> kvm_write_guest(), and the few places - if any - that need to force > >> transversing of the gfn mappings, get renamed to > >> kvm_write_guest_uncached ? > >> > >Good idea. I do not see any places where kvm_write_guest_uncached is > >needed from a brief look. Avi? > > > > kvm_write_guest_cached() needs something to supply the cache, and > needs recurring writes to the same location. Neither of these are > common (for example, instruction emulation doesn't have either). > Correct. Missed that. So what about changing steal time to use kvm_write_guest_cached()? > >> > >> If done like you said, time spent on the hypervisor is accounted as > >> steal time. I don't think it is. > >I thought that this is the point of a steal time. Running other > >tasks/guests is a hypervisor overhead too after all :) Also what about > >time spend serving host interrupts between put/get? It will not be > >accounted as steal time, correct? > > With accurate interrupt time accounting, it should be. Otherwise > general hypervisor overhead is not steal time. > > (i.e. if the host is not overcommitted, steal time should be close to zero). > -- 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
