Re: [Qemu-devel] Speed menu for GTK interfaace

[Programmingkid]

On Jan 3, 2017, at 3:59 AM, Gerd Hoffmann wrote:

> On So, 2017-01-01 at 13:15 -0500, Programmingkid wrote:
>> Hello, I was wondering if you would accept a patch that added a Speed
>> menu to the GTK interface. This would allow the user to change how
>> much CPU time the emulated CPU would see. 
> 
> /me wonders what exactly would the menu entries do?
> 
> cheers,
>  Gerd

It is quite simple, there would be a 100% to a 1% menu item. It would look like
this:

Speed
-------
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
1%


Each menu item would call cpu_throttle_set(). The value sent to this function 
would
be determined like this:
speed = -1 * menu_number + 100;

speed would be sent to the cpu_throttle_set() function. This function would 
reduce
the CPU usage of QEMU on the host. 

Why would someone want to slow down QEMU?
- The user is using a laptop and don't want it to heat up.
- The user wants to slow down a video game that is a little too challenging.
- The user wants to save energy.
- The user wants to conduct some kind of stress test on a program and see how
it handles under low cpu resources. 

Hope this helps. Thank you for responding.