From owner-freebsd-current  Wed May 29  1: 2:47 2002
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Date: Wed, 29 May 2002 17:02:42 +0900
From: Seigo Tanimura <tanimura@r.dl.itc.u-tokyo.ac.jp>
To: John Baldwin <jhb@FreeBSD.org>
Cc: Seigo Tanimura <tanimura@r.dl.itc.u-tokyo.ac.jp>,
	current@FreeBSD.org
Subject: Re: preemption across processors
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On Wed, 29 May 2002 16:13:13 +0900,
  Seigo Tanimura <tanimura@r.dl.itc.u-tokyo.ac.jp> said:

tanimura> Maybe we can solve both of the issues above by roughly checking if a
tanimura> thread can keep spinning without acquiring any locks, in the similar
tanimura> way as we do for a spin mutex.  First, test the following conditions:

tanimura> - The owner of the mutex has not changed.
tanimura> - The owner is on a processor.

- The priority of the curent thread has not changed.

If some other thread spins for a mutex held by the current thread, we
may have to propagate the priority of the other thread.

-- 
Seigo Tanimura <tanimura@r.dl.itc.u-tokyo.ac.jp> <tanimura@FreeBSD.org>

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