[PATCH] preempt-kernel on 2.4.19-pre2-ac2 bugfix

From: Robert Love (rml@tech9.net)
Date: Mon Mar 04 2002 - 19:23:10 EST

The same schedule_tail bug affecting 2.5 affects 2.4 with O(1). I.e.,
2.4.19-pre2-ac2.

In recent O(1) scheduler releases, an optimization was made that removed
schedule_tail from UP kernels. This causes the initial preempt_count of
a new task, which starts at 1, to never decrement to zero and thus never
become preemptible. CONFIG_PREEMPT requires schedule_tail, too.

Users of 2.4+O(1)+preempt (i.e. -ac) should use this patch:

        http://www.kernel.org/pub/linux/kernel/people/rml/preempt-kernel/v2.4/preempt-kernel-rml-2.4.19-pre2-ac2-2.patch

instead. Thanks to everyone who pointed out the lousy performance. Enjoy,

        Robert Love

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