> On Sat, 16 Dec 2006, [EMAIL PROTECTED] wrote: > >>> On Fri, 15 Dec 2006, Joseph Miller wrote: > > [..snip..] > >> Malc, >> >> Thanks, >> I think that this was my problem. I didn't realize that the usb tablet >> would cause such a slowdown. The usb tablet is such a useful feature, >> I'm >> sure it is commonly used. Maybe a warning could be provided so that >> users >> would know it has some performance quirks. Maybe I can look at the code >> and find out why it is so much slower? Maybe this is a general usb >> problem? > > You think? As in: tried with and without USB and top reports much higher > CPU usage? In any case do not rely on top(1) too much, as mentioned in > the post for certain CPU usage patterns Linux just does not provide a > meaningful idleness information (which top uses). > > Again as mentioned in the post, i have seen 30%-40% difference between > "real" idleness and what the kernel reports via proc, but 70% is a bit > too much. The negative impact of USB (tablet only?) on the load was > mentioned a few times on the ML and in private conversations with > Anthony Liguori and since there was no progress in this area i doubt > that there's much you can do apart from reporting the issue once again. > > Apparently you wont find much symphaty when reporting the speed issues > while kqemu is active. So i'd suggest to: > > a. Measure and report the difference without kqemu > b. Use something more reliable than top(1) > > -- > vale >
Yeah, I said "I think" because I wanted to use a decent benchmark to actually test the results. I threw in a test against VMPlayer as well. I found that with USB tablet emulation, Qemu was approximately only half as fast as it could operate without it. I did NOT perform these tests without KQEMU for two reasons 1) the *concept* that USB tablet emulation slows down Qemu can be shown either way and 2) I can't stand waiting around for hours and hours while Qemu translates code, sorry. At this particular time, I'm really only interested in this particular case because I use it for production use and many non-developer users are wanting to do the same thing. The only major difference that I found between Qemu+KQEMU and VMPlayer was that VMPlayer is about 4x faster when it comes to memory access. You can view my results at: http://www.calcmaster.net/qemu/benchmarks-20061216/ -Joseph _______________________________________________ Qemu-devel mailing list Qemu-devel@nongnu.org http://lists.nongnu.org/mailman/listinfo/qemu-devel
