On Tuesday 18 December 2007 16:30:08 Avi Kivity wrote: > Rusty Russell wrote: > > Yes, I pondered this when I wrote the code. On the one hand, it's a > > low-probability pathological corner case, on the other, your patch > > reduces the number of timer reprograms in the normal case. > > One thing that came up in our discussions is to let the host do the > timer processing instead of the guest. When tx exit mitigation is > enabled, the guest bumps the queue pointer, but carefully refrains from > kicking the host. The host polls the tx pointer using a timer, kicking > itself periodically; if polling yields no packets it disables tx exit > mitigation. This saves the guest the bother of programming the timer, > which presumably requires an exit if the timer is the closest one to > expiration. > > [btw, this can be implemented in virtqueue rather than virtio-net, no?] Yes, the current patch is a hack (look at the hardcoded constant); wanted to see how much it helps, if any. More sophisticated timer management would be a definite win... funny, I have a patch here which helps that.... Rusty. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
