Brad, I think the 0x20 (32ms) value might be fine for something like VNC display, but on a local display the mouse response is noticeably slow (for me at least.) I tried using 0x0a (10), same as the plain USB mouse, but the idle CPU utilization was still around 10%. What is really odd is that this was not a problem in older versions of QEMU, unless I'm reading data incorrectly. Do you know what else might have changed? I will look as well and see if I can apply some logic to this. I suspect it's probably something with the new clock mechanism, but it still doesn't make a lot of sense to me.
I've looked at both Windows 2000 and XP guests and seen similar results so far with the latest QEMU/KQEMU combination. The good news at least is that the 0x0a interval seems very smooth even on a local display, but certainly is much friendlier than the CVS version on the CPU. Still, 10% idle usage is quite high. If it can't logically be fixed to provide both a) low idle CPU and b) smooth local display response, then I might just post a runtime option patch allowing the user to configure the interval on the command line. I'm not sure how correct that is, but it would be useful to me at least. - Leo Reiter Brad Campbell wrote: > Lonnie Mendez wrote: > >> 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. > > Indeed. I'm not quite sure how or why I did that in the 1st place as the > tablet started life as a copy of the mouse in any case. > > I've had good drag through the specs and all the data sheets for mouse > chips I could find out there and most of them seem to recommend a value > no faster than 8ms. > > This drops the cpu utilisation of a Windows guest while idle about 75% > when using -usbdevice tablet > I've not noticed any change in usability or mouse responsiveness. > (I played with values up to 0xFF but after about 0x20 there seemed to be > immeasurable/no difference) > -- Leonardo E. Reiter Vice President of Product Development, CTO Win4Lin, Inc. Virtual Computing that means Business Main: +1 512 339 7979 Fax: +1 512 532 6501 http://www.win4lin.com _______________________________________________ Qemu-devel mailing list Qemu-devel@nongnu.org http://lists.nongnu.org/mailman/listinfo/qemu-devel