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From: David Mosberger <davidm@napali.hpl.hp.com>
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Date: Mon, 29 Jul 2002 14:48:39 -0700
To: "Van Maren, Kevin" <kevin.vanmaren@unisys.com>
Cc: "'Matthew Wilcox'" <willy@debian.org>,
       "'linux-kernel@vger.kernel.org'" <linux-kernel@vger.kernel.org>,
       "'linux-ia64@linuxia64.org'" <linux-ia64@linuxia64.org>
Subject: RE: [Linux-ia64] Linux kernel deadlock caused by spinlock bug
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>>>>> On Mon, 29 Jul 2002 16:29:09 -0500, "Van Maren, Kevin" <kevin.vanmaren@unisys.com> said:

  Van> Yes, but that isn't the point: unless you eliminate all rw
  Van> locks, it is conceptually possible to cause a kernel deadlock
  Van> by forcing contention on the locks you didn't remove, if the
  Van> user can force the kernel to acquire a reader lock and if
  Van> something else needs to acquire the writer lock.  Correctness
  Van> is the issue, not performance.

I agree with Kevin here.  There must be some argument as to why
readers cannot indefinitely lock out a writer.  A probabilistic
argument is fine, but just saying "contention doesn't happen"
certainly isn't good enough.

	--david
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