> > > > +{ 'command': 'balloon_drop_cache', 'data': {'value': > > > > +'DropCacheType'} } > > > > > > Also, as noted in the man page quote above, it is recommended to > > > call > > > sync() to minimise dirty pages. Should we have a way to request a > > > sync as part of this monitor command. > > > > > > More generally, it feels like this is taking as down a path towards > > > actively managing the guest kernel VM from the host. Is this really > > > a path we want to be going down, given that its going to take us > > > into increasing non-portable concepts which are potentially > > > different for each guest OS kernel. Is this drop caches feature at > > > all applicable to Windows, OS-X, *BSD guest OS impls of the balloon > > > driver ? If it is applicable, are the 3 fixed constants you've > > > > No. > > > > > defined at all useful to those other OS ? > > > > > > > Maybe they are not. > > I agree that there are too Linux specific. And I did more than needed. > > Actually, I just want to drop the clean cache, do more than that is > > too heavy and no good for performance. > > > > > I'm warying of us taking a design path which is so Linux specific it > > > isn't useful elsewhere. IOW, just because we can do this, doesn't > > > mean we should do this... > > > > > > > Agree. > > I can see an argument for giving the guest a hint about what's going on and > letting the guest decide what it's going to do - so telling the guest that a > migration is happening and you'd like it to make the hosts life easy seems > reasonable and it doesn't make any guest OS assumptions. > That's much better. Thanks! Liang -- 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