Re: Subject: PATCH : offline scheduler ( some refer to it as a CPU isolation )

[raz ben yehuda <raziebe@013.net>]

On Sun, 2009-04-19 at 03:23 +0200, Leon Woestenberg wrote:
> Raz,
> 
> On Sat, Apr 18, 2009 at 8:57 PM, raz ben yehuda <raziebe@013.net> wrote:
> > offsched is a platform aimed to assign a service to an off-lined processor.
> > Motivation is explained in:
> > http://sos-linux.svn.sourceforge.net/viewvc/sos-linux/offsched/trunk/Documentation/OFFSCHED.pdf
> 
> I quickly glanced over but could not find a comparison with other methods?
> 
> 
> Suppose I run /bin/init with a certain CPU affinity (not covering all
> CPUs) and then run my own specific service on the remaining CPUs, how
> would this differ from your approach?
First , not all services are children of init. there are workqueues,
kernel daemons, softirqs and so on. offlet provides hard real time,in
the sense that one can pre-determine how long an operation cost, it is
NMI mode after all. Also, this is why i chose to implement a 1us timer,
because i can do it.
> >From what I quickly gathered, you are running parts of the kernel
> space on the second CPU set, or is that too simple a statement?
I am running **no kernel** on the offloaded processors, but offsched code, 
and the rest of the processors run the "kernel". 
> 
> Looks like a very fresh approach, nice project!
Thank you. i appreciate it.  
> Regards,