From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: just an observation about USB Date: Wed, 14 Oct 2015 22:04:00 +0200 Message-ID: <561EB530.6010605@redhat.com> References: <561EAF76.1010105@eggo.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit To: "Eric S. Johansson" , kvm@vger.kernel.org Return-path: Received: from mail-wi0-f180.google.com ([209.85.212.180]:34168 "EHLO mail-wi0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753579AbbJNUEE (ORCPT ); Wed, 14 Oct 2015 16:04:04 -0400 Received: by wicgb1 with SMTP id gb1so144599588wic.1 for ; Wed, 14 Oct 2015 13:04:03 -0700 (PDT) In-Reply-To: <561EAF76.1010105@eggo.org> Sender: kvm-owner@vger.kernel.org List-ID: On 14/10/2015 21:39, Eric S. Johansson wrote: > update from the NaturallySpeaking in a VM project. > > don't remember what I told you before but, yes I can now send keystroke > events generated by speech recognition in the Windows guest into the > Linux input queue. I can also extract information from the Linux side, > and have it modify the grammar on the Windows side. The result of > activating that grammar is that I can execute code on either side in > response to speech recognition commands. it's fragile as all hell but > I'm the only one using it so far. :-) That's awesome! What was the problem? > Latency is a bit longer than I like. USB and network connections break > every time I come out of suspend part at least I don't have to use > Windows all the time. > > One thing is puzzling though. Windows, in idle, consume something like > 15 to 20% CPU according to top. I turn on NaturallySpeaking, the > utilization climbs to him roughly 30 to 40%. I turn on the microphone > and utilization jumps up to 80-110%. In other words, it takes up a > whole core. USB is really expensive because it's all done through polling. Do that in hardware, and your computer is a bit hotter; do that in software (that's what VMs do) and your computer doubles as a frying pan. If you have USB3 drivers in Windows, you can try using a USB3 controller. But it's probably going to waste a lot of processing power too, because USB audio uses a lot of small packets, making it basically the worst case. Paolo