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From: GZ Nianguan E.T. <opensource <at> gznianguan.com>
Subject: Re: SupeReNicer support for X2Go Server
Newsgroups: gmane.linux.terminal-server.x2go.devel
Date: Wednesday 13th November 2013 10:15:04 UTC (over 4 years ago)

The renicer just adjust the execution priority of a suspended session.
Where you'd see a noticeable impact would be in a situation where you 
have a lot of suspended users.
Which may be the normal case in a academic situation where you have 
significantly more user accounts than termial seats.
Lets say you have 10-20 active terminals and 50-100 suspended users.  By 
dropping the priority of the suspended sessions to rock bottom, the 
server will do everything else first... then tend to the suspended 
session on its "spare time".

As some have mentioned already...
By it self, on any given hardware, it does not save power...
But it does increase the amount of actively suspended users you can run 
on that hardware (while still maintaining an acceptable performance), 
thereby reducing the hardware requirement.

But together with CPU throttling based on how many active sessions you 
have and what those users may be doing...  you do save power...

In a traditional server environment you'd probably benefit from the 
renicer... however getting into CPU throttling and stuff like that to 
shave a few watts of your consumption is not really worth it.

but when your trying to build a terminal server with a 50-100w power 
envelope...  and you want this particular server to serve 10-20 active 
terminals. And you're wanting to be able to run the whole system on the 
smallest possible solar power setup... That's when you need to get 

Every saved watt * daily run time = significant impact on power system 
requirement and cost.

Best Regards,

On 13. nov. 2013 08:29, Mike Gabriel wrote:
> Hi all,
> nice discussion going on...
> On  Di 12 Nov 2013 19:31:38 CET, Orion Poplawski wrote:
>> On 11/05/2013 09:12 AM, Mike Gabriel wrote:
>>> Hi all,
>>> the (x2goserver.git master) just received a code
>>> patch from
>>> Guangzhou Nianguan Electronics Technology Co.Ltd, an open source
>>> company in
>>> Asia that plans to use X2Go for school setups in areas where
>>> electricity is a
>>> rare resource. They plan to build cost-effective and energy-effective
>>> embedded
>>> thin clients running X2Go.
>>> The patch we received adds a feature to X2Go Server called
>>> SupeReNicer [1] and
>>> it is a tool that hooks into x2gocleansessions. It renices suspended
>>> sessions
>>> to nice level 19 and renices them again to nice level 0 once they
>>> change there
>>> status from suspended to running.
>> Is there any evidence that nicing something actually save energy?  I
>> wouldn't have thought so.
> The intention of the renicing code is rather about squeezing more users
> on one server than reducing power consumption.
> If anyone indeed does some power measuring, please keep us in the loop
> about your results.
> Mike
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