On 2011-02-08 10:05, Aurelien Jarno wrote: > Jan Kiszka a écrit : >> On 2011-02-08 09:08, Paolo Bonzini wrote: >>> On 02/08/2011 08:26 AM, Aurelien Jarno wrote: >>>> I forget to remember when we decided that AIO should be implemented on >>>> any host OS. Any pointer? >>> To be fair, I/O-heavy workloads are almost unusable without AIO. For >>> Window targets, they also crash under SMP due to the Windows AP >>> watchdog. But then TCG and SMP do not go very well together anyway. >>> >>> However, I think deprecating Win32 support would be a very bad idea. >> >> It would be too early at this point. >> >> But if Windows is once the only reason to keep tons of hardly tested >> code paths around or to invest significant additional effort to change >> logic or interfaces in this area, than I would prefer that step. I'm >> hacking on IOTHREAD vs. !IOTHREAD for some weeks now, and all those >> subtle differences are really a PITA and source of various breakages. >> >> People interested in that platform should finally realize that its fate >> is coupled to reducing the #ifdefs as well as the design differences we >> see right now and even more in the future. >> > > The guilty here is IOTHREAD. Windows support predates IOTHREAD concept, > it's just that people who introduce IOTHREAD didn't care about Windows > support at all and added these #ifdef. Disabling Windows support because > of that is not fair.
The TCG execution model won't scale long-term. It's already a main to boot a quad or just dual core VM, even more when your host has at least as many real cores. I'm sure we'll see multi-threaded TCG CPUs in the future, and the iothread will just be one of 7, 17 or 257 threads. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux
