[Qemu-devel] WinXp Guest clock drift

[Qemu-devel] WinXp Guest clock drift

[Brad Campbell]

Does anyone else notice that unless you run an ntp client inside the guest, that time drifts so 
much/so fast as to be unusable?

I work around this by using an ntp client but I thought it worth mentioning.

Brad
-- 
"Human beings, who are almost unique in having the ability
to learn from the experience of others, are also remarkable
for their apparent disinclination to do so." -- Douglas Adams

Re: [Qemu-devel] WinXp Guest clock drift

[Mike Swanson]

Well, this is probably a nuisance in all emulators :p

They only way to actually solve it that I know of is to use KQEMU.

-- 
Mike

Re: [Qemu-devel] WinXp Guest clock drift

[Magnus Damm]

On Mon, 21 Mar 2005 23:15:24 -0800, Mike Swanson
<mikeonthecomputer@gmail.com> wrote:
> Well, this is probably a nuisance in all emulators :p

Does it have to be that way? I mean - if a media player can keep track
of the time of a movie (with and without sound) then wouldn't it be
possible for other applications like emulators to keep accurate time?

I do not know how the time is handled in QEMU, but I wrote code some
years ago that monitored itself with gettimeofday() and adjusted the
drift on the fly.
 
/ magnus

Re: [Qemu-devel] WinXp Guest clock drift

[Brad Campbell]

Magnus Damm wrote:
> On Mon, 21 Mar 2005 23:15:24 -0800, Mike Swanson
> <mikeonthecomputer@gmail.com> wrote:
> 
>>Well, this is probably a nuisance in all emulators :p
> 
> 
> Does it have to be that way? I mean - if a media player can keep track
> of the time of a movie (with and without sound) then wouldn't it be
> possible for other applications like emulators to keep accurate time?
> 
> I do not know how the time is handled in QEMU, but I wrote code some
> years ago that monitored itself with gettimeofday() and adjusted the
> drift on the fly.

I actually find all sorts of oddities with timing and qemu emulation. Sometimes when installing 
stuff in a windows guest the guest slows to a crawl until I move the mouse around or drag a window 
or something similar. Almost like it starts to go to sleep until it gets some user interaction.

There are a number of emulation oddities thus far, I just get used to them and work around them. I 
guess I should actually have a go at debugging them really.


-- 
"Human beings, who are almost unique in having the ability
to learn from the experience of others, are also remarkable
for their apparent disinclination to do so." -- Douglas Adams

Re: [Qemu-devel] WinXp Guest clock drift

[Magnus Damm]

On Tue, 22 Mar 2005 12:21:47 +0400, Brad Campbell <brad@wasp.net.au> wrote:
> Magnus Damm wrote:
> > On Mon, 21 Mar 2005 23:15:24 -0800, Mike Swanson
> > <mikeonthecomputer@gmail.com> wrote:
> >
> >>Well, this is probably a nuisance in all emulators :p
> >
> >
> > Does it have to be that way? I mean - if a media player can keep track
> > of the time of a movie (with and without sound) then wouldn't it be
> > possible for other applications like emulators to keep accurate time?
> >
> > I do not know how the time is handled in QEMU, but I wrote code some
> > years ago that monitored itself with gettimeofday() and adjusted the
> > drift on the fly.
> 
> I actually find all sorts of oddities with timing and qemu emulation. Sometimes when installing
> stuff in a windows guest the guest slows to a crawl until I move the mouse around or drag a window
> or something similar. Almost like it starts to go to sleep until it gets some user interaction.

I second that observation.

> There are a number of emulation oddities thus far, I just get used to them and work around them. I
> guess I should actually have a go at debugging them really.

The same goes for me...

/ magnus

Re: [Qemu-devel] WinXp Guest clock drift

[John R. Hogerhuis]

On Tue, 2005-03-22 at 12:21 +0400, Brad Campbell wrote:

> I actually find all sorts of oddities with timing and qemu emulation. Sometimes when installing 
> stuff in a windows guest the guest slows to a crawl until I move the mouse around or drag a window 
> or something similar. Almost like it starts to go to sleep until it gets some user interaction.
> 

FWIW, that is one of those archetypical problems that crops up in event
driven software. It is a sure sign that an event has gone missing or is
being ignored. Events can be interrupts, or data appearing on an
interface that is polled. In this case it would probably have to do with
emulated hardware.

Just a general comment, but maybe it will jog something loose for the
right person...

-- John.

Re: [Qemu-devel] WinXp Guest clock drift

[Brad Campbell]

Mike Swanson wrote:
> Well, this is probably a nuisance in all emulators :p
> 
> They only way to actually solve it that I know of is to use KQEMU.
> 

Umm forgot to mention, I'm using KQEMU.

-- 
"Human beings, who are almost unique in having the ability
to learn from the experience of others, are also remarkable
for their apparent disinclination to do so." -- Douglas Adams