svn commit: r184199 - in head/sys: kern sys

[John Baldwin]

On Thursday 23 October 2008 03:55:38 am David Xu wrote:
> Author: davidxu
> Date: Thu Oct 23 07:55:38 2008
> New Revision: 184199
> URL: http://svn.freebsd.org/changeset/base/184199
> 
> Log:
>   Actually, for signal and thread suspension, extra process spin lock is
>   unnecessary, the normal process lock and thread lock are enough. The
>   spin lock is still needed for process and thread exiting to mimic
>   single sched_lock.

With thread_lock() it is not safe to drop a mutex while holding thread_lock().  
Instead, it can result in a deadlock.  Peter has a test case that deadlocks 
due to these changes.  Please revert this.

-- 
John Baldwin