sched: Ensure a task has a non-normalized vruntime when returning back to CFS
sched: Ensure a task has a non-normalized vruntime when returning back to CFS

Current code ensures that a task has a normalized vruntime when switching away
from the fair class, but it does not ensure the task has a non-normalized
vruntime when switching back to the fair class.

This is an example breaking this consistency:

  1. a task is in fair class and !queued
  2. changes its class to RT class (still !queued)
  3. changes its class to fair class again (still !queued)

Signed-off-by: Byungchul Park <e40c5f8992a9890dae9876367c0c4ab1dc1f880b@lge.com>
Signed-off-by: Peter Zijlstra (Intel) <3fddac958924aef220f202ca567388ddab3f14a8@infradead.org>
Cc: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>
Cc: Mike Galbraith <3cfa3897b7f55b5396b7a47c83b66325184bc9b4@gmx.de>
Cc: Peter Zijlstra <3fddac958924aef220f202ca567388ddab3f14a8@infradead.org>
Cc: Thomas Gleixner <00e4cf8f46a57000a44449bf9dd8cbbcc209fd2a@linutronix.de>
Link: http://lkml.kernel.org/r/1439197375-27927-1-git-send-email-e40c5f8992a9890dae9876367c0c4ab1dc1f880b@lge.com
Signed-off-by: Ingo Molnar <9dbbbf0688fedc85ad4da37637f1a64b8c718ee2@kernel.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs