On Tue, Nov 03, 2009 at 03:46:07PM -0200, Marcelo Tosatti wrote: > On Tue, Nov 03, 2009 at 12:35:08PM -0200, Glauber Costa wrote: > > Right now, we issue cpu creation from the i/o thread, and then shoot a thread > > from inside that code. Over the last months, a lot of subtle bugs were reported, > > usually arising from the very fragile order of that initialization. > > > > I propose we rethink that a little. This is a patch that received basic testing > > only, and I'd like to hear on the overall direction. The idea is to issue the new > > thread as early as possible. The first direct benefits I can identify are that > > we no longer have to rely at on_vcpu-like schemes for issuing vcpu ioctls, since > > we are already on the right thread. Apic creation has far less spots for race > > conditions as well. > > > > I am implementing this on qemu-kvm first, since we can show the benefits of it > > a bit better in there (since we already support smp) > > > > Let me know what you guys think > > Makes sense to me. You still need on_vcpu for issuing vcpu ioctls though > (after initialization). Yes, but I believe we can avoid most of them. There is a performance hit of using it, but I am not so concerned with that. The nasty races that arises from it, are more a concern to me. -- 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
