On 12/16/2015 01:54 PM, Christian Borntraeger wrote: > On 12/09/2015 09:35 PM, Paolo Bonzini wrote: >> >> >> On 26/11/2015 11:39, Paolo Bonzini wrote: >>> I would really prefer to get rid of vring.c as soon as the infrastructure >>> makes it possible---even if it's faster. We know what makes virtio.c >>> slower, and it's simpler to fix virtio.c than to convert all the other >>> models to vring.c _plus_ make vring.c safe for migration. >> >> I've now pushed some optimizations of exec.c to the same place (branch >> dataplane, git://github.com/bonzini/qemu.git). Basically if the length >> of an address_space_read is constant, and the target ends up being RAM, >> the compiler can inline address_space_read in the caller and in >> particular eliminate the memcpy. > > Just some quick remarks before I leave into vacation: > > Performance seems to be better than the initial version.
In fact, it seems to be faster than 2.5-rc4. At least with the one single test case on null block devices that I run.
