Subject: Re: kprintf locking problem.
To: Anders Magnusson <ragge@ludd.luth.se>
From: Jason R Thorpe <thorpej@zembu.com>
List: tech-smp
Date: 06/03/2001 11:11:46
On Sun, Jun 03, 2001 at 07:04:06PM +0200, Anders Magnusson wrote:
> If the master CPU is spinning on a lock that is not taken by a
> __cpu_simple_lock(), then it will be handled by the SPINLOCK_SPIN_HOOK.
> But you're right, if there is a printf inside another spinlock
> then the same problem rises. That is a good reason to just do the check
> inside __cpu_simple_lock(), and everything would be fine.
Not quite true, unfortunately -- SPINLOCK_SPIN_HOOK is used only for
lockmgr() spin locks -- simple_lock() is not affected by it.
--
-- Jason R. Thorpe <thorpej@zembu.com>