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

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

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/