From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1G4wfU-0003AX-6p for qemu-devel@nongnu.org; Mon, 24 Jul 2006 05:24:04 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1G4wfT-00039Y-FM for qemu-devel@nongnu.org; Mon, 24 Jul 2006 05:24:03 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1G4wfT-00039V-AD for qemu-devel@nongnu.org; Mon, 24 Jul 2006 05:24:03 -0400 Received: from [24.93.47.40] (helo=ms-smtp-01.texas.rr.com) by monty-python.gnu.org with esmtp (Exim 4.52) id 1G4wgW-0002n1-Nu for qemu-devel@nongnu.org; Mon, 24 Jul 2006 05:25:09 -0400 Received: from vaio (cpe-67-9-160-120.austin.res.rr.com [67.9.160.120]) by ms-smtp-01.texas.rr.com (8.13.6/8.13.6) with ESMTP id k6O9O0Rn025316 for ; Mon, 24 Jul 2006 04:24:00 -0500 (CDT) Subject: Re: [Qemu-devel] Performance issues with -usb From: Lonnie Mendez In-Reply-To: <44C48DAD.9010301@wasp.net.au> References: <44C48DAD.9010301@wasp.net.au> Content-Type: text/plain Date: Mon, 24 Jul 2006 04:23:58 -0500 Message-Id: <1153733038.4270.8.camel@vaio> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org On Mon, 2006-07-24 at 13:06 +0400, Brad Campbell wrote: > G'day all, > > Just a diary note or similar. > > I've been playing with skype under win2k under qemu with -kernel-kqemu and the alsa audio driver. > > 1st. The user-net driver appears to be a problem for skype but the tap driver works nicely. > > 2nd. I was having awful problems with the audio. The app was reporting failures of either the dac or > adc apparently randomly and when it did work it was rather intermittent. > > I noticed that with -usb -usbdevice tablet that qemu sits at about 20% cpu usage (on this machine > which is a Pentium-M 1.2G which idles at 600Mhz) whereas without -usb qemu idles completely. > > In addition to this, without -usb.. skype works almost perfectly. There is the occasional audio > glitch (as you would expect) but it does everything it is supposed to do quite nicely. > > I'm using all the latest gear. A 2.6.18-rc2 host kernel, Latest Qemu CVS and the -pre9 kernel > accelerator. Win2k SP4 as a guest with either 256 or 384M of ram depending on my mood :) > > I'm going to have a dig around in the USB stuff when I get the chance, but it's more of a fyi and > for google that I post it here. Perhaps tweaking the value of ep_bInterval for the tablet's status change endpoint would help? The endpoint descriptor for the tablet currently has this at 3 milliseconds. The hid mouse reports a 10 millisecond polling interval. excerpt from qemu_tablet_config_descriptor in hw/usb-hid.c: /* one endpoint (status change endpoint) */ 0x07, /* u8 ep_bLength; */ 0x05, /* u8 ep_bDescriptorType; Endpoint */ 0x81, /* u8 ep_bEndpointAddress; IN Endpoint 1 */ 0x03, /* u8 ep_bmAttributes; Interrupt */ 0x08, 0x00, /* u16 ep_wMaxPacketSize; */ 0x03, /* u8 ep_bInterval; (255ms -- usb 2.0 spec) */