Re: [PATCH try 5] CFS: Add hierarchical tree-based penalty.

[Ingo Molnar <mingo@elte.hu>]

* William Pitcock <nenolod@dereferenced.org> wrote:

> Hi,
> 
> ----- "Ingo Molnar" <mingo@elte.hu> wrote:
> 
> > * William Pitcock <nenolod@dereferenced.org> wrote:
> > 
> > > Inspired by the recent change to BFS by Con Kolivas, this patch
> > causes 
> > > vruntime to be penalized based on parent depth from their root task
> > 
> > > group.
> > > 
> > > I have, for the moment, decided to make it a default feature since
> > the 
> > > design of CFS ensures that broken applications depending on task 
> > > enqueue behaviour behaving traditionally will continue to work.
> > 
> > Just curious, is this v5 submission a reply to Peter's earlier review
> > of 
> > your v3 patch? If yes then please explicitly outline the changes you
> > did 
> > so that Peter and others do not have to guess about the direction your
> > 
> > work is taking.
> 
> I just did that in the email I just sent.  Simply put, I was talking 
> with Con a few weeks ago about the concept of having a maximum amount 
> of service for all threads belonging to a process.  This did not work 
> out so well, so Con proposed penalizing based on fork depth, which 
> still allows us to maintain interactivity with make -j64 running in 
> the background.
> 
> Actually, I lie: it works great for server scenarios where you have 
> some sysadmin also running azureus.  Azureus gets penalized instead, 
> but other apps like audacious get penalized too.

Thanks for the explanation!

	Ingo