On Mon, Sep 21, 2015 at 11:44:38PM +0200, Marc-André Lureau wrote: > Hi > > On Mon, Sep 21, 2015 at 9:29 PM, Michael S. Tsirkin <m...@redhat.com> wrote: > >> Can this be considered a future enhancement? > > > > What's the big issue? Just count the devices that need a shared one, if > > that count is 0 reallocate with shared == false. > > > But then it should also VHOST_SET_LOG_BASE all the other devices with > the new log, unless you want to tackle only the future log users. So > it needs to track all the users of the log.
We already do this. Same applies to non-memfd->memfd switch. > 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. 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. > -- > Marc-André Lureau
