On 10/22/2012 02:55 PM, Jan Kiszka wrote: >> Since the userspace change is needed the idea is dead, but if we could >> implement it I do not see how it can hurt the latency if it would be the >> only mechanism to use coalesced mmio buffer. Checking that the ring buffer >> is empty is cheap and if it is not empty it means that kernel just saved >> you a lot of 8 bytes exists so even after iterating over all the entries there >> you still saved a lot of time. > > When taking an exit for A, I'm not interesting in flushing stuff for B > unless I have a dependency. Thus, buffers would have to be per device > before extending their use. Any mmio exit has to flush everything. For example a DMA caused by an e1000 write has to see any writes to the framebuffer, in case the guest is transmitting its framebuffer to the outside world. -- error compiling committee.c: too many arguments to function -- 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
