vmware strange scheduling priority

vmware strange scheduling priority

[Peter Enderborg]

Im playing with vmware 4.0 workstation. And it do some strange things.
I start vmware with nice and I got this:
26499 pme       19  19 95980  93M 95020 R N    12 32.6 24.8   8:55 
vmware-vmx
26439 pme       19  19  8416 8008  7692 R N     8  3.2  2.0   2:02 
vmware-vmx
26492 pme        6 -10 95980  93M 95020 R <    12  2.6 24.8   0:34 
vmware-vmx
26409 pme       19  19  4900 3916  2484 S N     0  1.0  1.0   0:29 vmware
26433 pme        5 -10  8416 8008  7692 S <     8  0.5  2.0   0:29 
vmware-vmx
26493 pme        5 -10  8056 7268  6988 S <     0  0.5  1.8   0:20 
vmware-mks
26495 pme        9   0 67672  65M 66888 S       0  0.2 17.4   0:11 
vmware-vmx


It have changed the prioority to -10 for some of its own tasks. How can 
that be done? Its a non suid binary started
by a normal user. It's very ugly, but Im more intressted in how it can 
be done.
The kernel is a 2.4.20.

Re: vmware strange scheduling priority

[Antonio Vargas]

On Mon, Jun 16, 2003 at 08:39:38PM +0200, Peter Enderborg wrote:
> Im playing with vmware 4.0 workstation. And it do some strange 
> things.
> I start vmware with nice and I got this:
> 26499 pme       19  19 95980  93M 95020 R N    12 32.6 24.8   8:55 
> vmware-vmx
> 26439 pme       19  19  8416 8008  7692 R N     8  3.2  2.0   2:02 
> vmware-vmx
> 26492 pme        6 -10 95980  93M 95020 R <    12  2.6 24.8   0:34 
> vmware-vmx
> 26409 pme       19  19  4900 3916  2484 S N     0  1.0  1.0   0:29 
> vmware
> 26433 pme        5 -10  8416 8008  7692 S <     8  0.5  2.0   0:29 
> vmware-vmx
> 26493 pme        5 -10  8056 7268  6988 S <     0  0.5  1.8   0:20 
> vmware-mks
> 26495 pme        9   0 67672  65M 66888 S       0  0.2 17.4   0:11 
> vmware-vmx
> 
> 
> It have changed the prioority to -10 for some of its own tasks. How 
> can that be done? Its a non suid binary started
> by a normal user. It's very ugly, but Im more intressted in how it 
> can be done.
> The kernel is a 2.4.20.

pure guessing here...
vmware relies on having kernel modules instaled.. perhaps
the do an ioctl to enter the module and then they spin
off some threads with nice -10 from inside?
 
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Re: vmware strange scheduling priority

[Petr Vandrovec]

On 15 Jun 03 at 20:59, Antonio Vargas wrote:
> On Mon, Jun 16, 2003 at 08:39:38PM +0200, Peter Enderborg wrote:
> > Im playing with vmware 4.0 workstation. And it do some strange 
> > things.
> > I start vmware with nice and I got this:
> > 26499 pme       19  19 95980  93M 95020 R N    12 32.6 24.8   8:55 
> > vmware-vmx
> > 26439 pme       19  19  8416 8008  7692 R N     8  3.2  2.0   2:02 
> > vmware-vmx
> > 26492 pme        6 -10 95980  93M 95020 R <    12  2.6 24.8   0:34 
> > vmware-vmx
> > 26409 pme       19  19  4900 3916  2484 S N     0  1.0  1.0   0:29 
> > vmware
> > 26433 pme        5 -10  8416 8008  7692 S <     8  0.5  2.0   0:29 
> > vmware-vmx
> > 26493 pme        5 -10  8056 7268  6988 S <     0  0.5  1.8   0:20 
> > vmware-mks
> > 26495 pme        9   0 67672  65M 66888 S       0  0.2 17.4   0:11 
> > vmware-vmx
> > 
> > 
> > It have changed the prioority to -10 for some of its own tasks. How 
> > can that be done? Its a non suid binary started
> > by a normal user. It's very ugly, but Im more intressted in how it 
> > can be done.
> > The kernel is a 2.4.20.
> 
> pure guessing here...
> vmware relies on having kernel modules instaled.. perhaps
> the do an ioctl to enter the module and then they spin
> off some threads with nice -10 from inside?

Nope. vmware-vmx is suid...
                                            Petr Vandrovec
                                            vandrove@vc.cvut.cz

P.S.: And if you play with default priority for VMware, do not
complain that it is slow as a molase...