How Resources are Shared in the SLES 11 Priority Scheduler - comment by carrie

Amir,
 
It is difficult to quantify CPU consumption changes between SLES 10 and SLES 11 because the accounting is completely different in SLES 11.   
 
But in general, most sites experience some increase in CPU usage, much of it in "system".  As with all new versions of software that adds improved features and greater value, you will see a slight uptick in CPU in SLES 11  just to account for the extra work being performed.   There  is, for example, an additional cost to the improved accuracy and granularity in keeping track of resource usage, and with the stonger enforcement of priorities.   The new operating system accounting and scheduling is orders of magnitude more precise.
 
In addition,  many of the small things that get done in and by the operating system have been moved to different places in the code in SLES11.  SLES11 is a complete re-architecture, and many things that ran somewhere else, now get bucketed into "system".  And there are a number of file system background tasks that run to a greater degree in system in SLES 11 compared to SLES 10.  So a comparison of that metric before and after is unfortunately apples to oranges.     
 
Thanks, - Carrie