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Subject: [PATCH] updated preempt-kernel
From: Robert Love <rml@tech9.net>
To: linux-kernel@vger.kernel.org
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Date: 20 Oct 2001 03:27:12 -0400
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Testers Wanted:

patches to enable a fully preemptible kernel are available at:
	http://tech9.net/rml/linux
for kernels 2.4.10, 2.4.12, 2.4.12-ac3, and 2.4.13-pre5.

What is this:

A preemptible kernel.  It lowers your latency.

What is New:

* sync with new kernel releases

* if HIGHMEM_DEBUG was on the preempt counter would be incremented at
times but never decremented.  this resulted in preemption becoming
permanently disabled.

* if HIGHMEM_DEBUG was not on, HIGHMEM would crash the system horribly
due to a case where preemption was enabled without a corresponding
disable.

* reapply dropped hunk to pgalloc to prevent reentrancy onto per-CPU
data

The next few patches are going to work on identifying any remaining
per-CPU variables that need explicit locking under preemption.

	Robert Love