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Date: Mon, 16 Aug 2004 21:43:21 -0700 (PDT)
From: Don Lewis <truckman@FreeBSD.org>
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Subject: thoughts on system hangs after panic()
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I suspect the cause of the system hangs after a panic that are keeping
crash dumps from working is one of the shutdown_pre_sync handlers
getting wedged.  The most likely culprit is syncer_shutdown(), but I
think any of the handlers could get wedged in kthread_suspend().

Either we should skip shutdown_pre_sync entirely if RB_NOSYNC is set, or
the handlers should obey this bit as appropriate.  The latter would
require a little more code to be touched, but would allow for more
flexibility.