Gregory Haskins wrote: > >> Later we'll have vcpu and thread_info point to each other and then you >> can do that kind of optimization. >> > > I am not familiar with thread_info, but if it solves the dangling pointer > problem, that sounds great.
It's fairly tricky, but it's the right way forward. It means a 1:1 association of a vcpu and a thread for the lifetime of the vcpu. > It sounds like you are in favor of leaving this optimization for a later > time. As long as you are ok with every interrupt related ioctl such as > KVM_APIC_MSG, and KVM_ISA_INTERRUPT posting a signal to itself, we can pull > this for now. Perhaps you can disable this by noticing that you're injecting an interrupt now (another icky variable in struct kvm_vcpu). > Conversely, if the thread_info approach isn't hard, I would prefer to get > this right now, as the double interrupt thing seems nasty to me. > > Alternatively, perhaps I can just replace irq.task with irq.pid? And I could > also replace irq.guest_mode with irq.guest_cpu. I will then record the pid > where today I record the task. Likewise, I can extract the guest_cpu (using > task_cpu(current)) where today I assign irq.guest_mode = 1. That would > effectively remove the dangling pointer problem while retaining the features > that I like. > pid can dangle just the same as a task pointer, only much worse. > Thoughts? > > >> Oh, and nobody said that the task waiting on the event is the same as >> the task running the vcpu. >> > > I'm a little confused by this statement. I don't use irq.task for assigning > a target for the event. That is all self contained in the eventfd. Its true > that some of the older designs used this as the send_sig() target, but the > assumption there was we were posting a signal to the entire PID, not a > specific TID. That could have been a bad assumption, but its moot now. Let > me know if you meant something else. > Strike that. I was confused. -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
