Avi Kivity wrote: > On 06/28/2010 10:30 AM, Dong, Eddie wrote: >>> >>> Several milliseconds of non-responsiveness may not be acceptable for >>> some applications. So I think queue_work_on() and a clflush loop is >>> better than an IPI and wbinvd. >>> >>> >> Probably we should make it configurable. For RT usage models, we do >> care about responsiveness more than performance, but for typical >> server useg model, we'd better focus on performance in this issue. >> WBINVD may perform much much better than CLFLUSH, and a mallicious >> guest repeatedly issuing wbinvd may greatly impact the system >> performance. >> > > I'm not even sure clflush can work. I thought you could loop on just > the cache size, but it appears you'll need to loop over the entire > guest address space, which could take ages. If RT usage model comes into reality, we may have to do in this way though pay with huge overhead :) Is there any RT customers here? > > So I guess we'll have to settle for wbinvd, just avoiding it when the > hardware allows us to. Yes, for now I agree we can just use wbinvd to emulate wbinvd :) Thx, Eddie -- 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
