hi On Tue, Sep 22, 2015 at 1:41 PM, Michael S. Tsirkin <m...@redhat.com> wrote: > There's a single log at the moment: > static struct vhost_log *vhost_log; > > But all devices are updated by the memory core, we don't > have a list in the vhost code.
Do you mean that all devices will have their memory listener restart the log, so they all point to the same global vhost_log? >> >> Is there a clear benefit >> >> of this? since the memory isn't shared without the memfd passed to >> >> another process and the overhead of memfd is probably quite small, and >> >> pre-shm or future resize will not use the shared memory already. >> > >> > For example, THP doesn't work for memfd at the moment, >> > so all accesses are a bit slower. >> >> What's THP? How is it slower once the fd is mmap? > > Transparent huge page. This process doesn't work for > memfd AFAIK. > >> > Really, I don't want to merge hacks. Switching from non memfd >> > to memfd but not back has all the signs of one. >> > Let's do it cleanly please. >> >> The current code isn't switching existing logs either. What would be >> simpler to do is to allocate a different log region for the "share" >> case. So there would be no need to switch other non-shareable logs (to >> the cost of using twice the memory needed). > > OK, that's not too bad. Let's go for it. ok, working on new patch -- Marc-André Lureau
