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Real-Time Preemption, -RT-2.6.10-rc2-mm1-V0.7.28-0

From:  Ingo Molnar <mingo@elte.hu>
To:  linux-kernel@vger.kernel.org
Subject:  [patch] Real-Time Preemption, -RT-2.6.10-rc2-mm1-V0.7.28-0
Date:  Wed, 17 Nov 2004 13:42:34 +0100
Cc:  Lee Revell <rlrevell@joe-job.com>, Rui Nuno Capela <rncbc@rncbc.org>, Mark_H_Johnson@Raytheon.com, "K.R. Foley" <kr@cybsft.com>, Bill Huey <bhuey@lnxw.com>, Adam Heath <doogie@debian.org>, Florian Schmidt <mista.tapas@gmx.net>, Thomas Gleixner <tglx@linutronix.de>, Michal Schmidt <xschmi00@stud.feec.vutbr.cz>, Fernando Pablo Lopez-Lezcano <nando@ccrma.Stanford.EDU>, Karsten Wiese <annabellesgarden@yahoo.de>, Gunther Persoons <gunther_persoons@spymac.com>, emann@mrv.com, Shane Shrybman <shrybman@aei.ca>, Amit Shah <amit.shah@codito.com>


i have released the -V0.7.28-0 Real-Time Preemption patch, which can be
downloaded from the usual place:

	http://redhat.com/~mingo/realtime-preempt/

this is a fixes & latency-reduction release.

Changes since a -V0.7.27-3:

 - made the UP-ioapic code a bit more conservative again - maybe some of
   the lockups are related?

 - removed the BKL from the sound code in a cleaner way and
   removed the quite fragile 'negative ->lock_depth' code. Much less
   intrusive than i originally thought, and much cleaner as well.

 - more fixes to the wakeup-timing logic, 4 false positives fixed in
   total, mostly related to new-task-wakeup not accurately starting the
   tracer.

 - fixed the mmx-memcpy related latency reported by Florian Schmidt and 
   others. Also turned off the MMX/SSE ops in the RAID code, which 
   can introduce similar latencies.

 - kgdb fix from Bill Huey

 - knfsd shutdown with-BKL-held fix

 - highmem compilation fix

 - profiling related crash fix

 - implemented 'direct-path' rescheduling to further reduce scheduling
   latency: the kernel will now in most cases go from try_to_wakeup()
   into the scheduler directly without re-enabling interrupts ever again
   (and thus not giving irq handlers a window to increase latency). This
   is also the final fix for irq nesting and irq-stack recursion.

 - turn off sync wakeups on PREEMPT_RT -> they are latency generators

to create a -V0.7.28-0 tree from scratch, the patching order is:

  http://kernel.org/pub/linux/kernel/v2.6/linux-2.6.9.tar.bz2
  http://kernel.org/pub/linux/kernel/v2.6/testing/patch-2.6...

http://kernel.org/pub/linux/kernel/people/akpm/patches/2....

http://redhat.com/~mingo/realtime-preempt/realtime-preemp...

	Ingo
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