[Cbe-oss-dev] [PATCH 0:7] assorted spusched fixes and new stuff (defered queuing and x_ctxt debug file)

[Luke Browning]

Re-posting patches.  

These patches are built on top of Christoph's patch which is not
included in this set.   Christoph's patch is at:

http://ozlabs.org/pipermail/cbe-oss-dev/2008-May/004730.html

Patches 0-5 are bug fixes and can be applied independently
Patch 6 & 7 implement new stuff.

Patch 6 implements deferred queuing for spu class 1 faults.  This is
expected to improve performance and solve some scheduling problems that
we are now experiencing.  This is a replacement for Andre Detsch's patch
where he just returned an arbitrary element from the run queue.  He was
seeing a problem where the scheduler was scheduling and unscheduling
contexts in a repeatable fashion.  Basically, the N-16th context needed
to be scheduled with the N+1 context which was never happening.

Patch 7 implements a new debug x_ctxt file for analyzing application
hangs and performance problems.  Something like this is needed to help
analyze these sorts of problems in the field.  Currently, we have no
visibility into these problems now and can't tell the difference between
application and kernel problems.  This will help.

Luke