[TIP/SCHED/DEVEL PATCH v3 0/6] sched: misc rt fixes

[Gregory Haskins <ghaskins@novell.com>]

Hi Ingo,

The following repositories

     git://git.kernel.org/pub/scm/linux/kernel/git/ghaskins/linux-2.6-hacks.git tip/sched/devel/rtbalance 

     ftp://ftp.novell.com/dev/ghaskins/tip-rt-fixes.tar.bz2

[
     *- Steve: I have also backported this to 2.6.26.3-rt5: *-

     ftp://ftp.novell.com/dev/ghaskins/PREEMPT_RT-rt-fixes.tar.bz2
]

apply to tip/sched/devel to pick up the following fixes for the RT
scheduler. 

[
	Changelog:

	v3:
	    *) fixed a bug in patch 6/6 in enqueue_pushable_task
	    *) backported from tip to 26.3-rt5
	
	v2: 
	    *) predicated newidle and double_lock changes on
	       CONFIG_PREEMPT to address a concern by Nick Piggin

	    *) fixed a build issue when DEBUG_PI_LIST is defined 

	v1:
	    *) initial release
]


These patches were developed in the interest of shorting latencies in
PREEMPT_RT, but they apply to the mainline scheduler as well, so I am
offering them here as well.

This has been tested under both 26.3-rt5 and tip/sched/devel on x86_64 for
both CONFIG_SMP and !CONFIG_SMP.

Comments/bug-fixes welcome!

Regards,
-Greg


---

Gregory Haskins (6):
      sched: create "pushable_tasks" list to limit pushing to one attempt
      plist: fix PLIST_NODE_INIT to work with debug enabled
      sched: add sched_class->needs_post_schedule() member
      sched: make double-lock-balance fair
      sched: pull only one task during NEWIDLE balancing to limit critical section
      sched: only try to push a task on wakeup if it is migratable


 include/linux/init_task.h |    1 
 include/linux/plist.h     |    9 ++-
 include/linux/sched.h     |    2 +
 kernel/sched.c            |   84 ++++++++++++++++++++++++---
 kernel/sched_rt.c         |  138 ++++++++++++++++++++++++++++++++++++++-------
 5 files changed, 201 insertions(+), 33 deletions(-)