svn commit: r184216 - head/sys/kern

John Baldwin jhb at
Tue Nov 4 14:09:42 PST 2008

On Thursday 23 October 2008 09:03:31 pm David Xu wrote:
> Author: davidxu
> Date: Fri Oct 24 01:03:31 2008
> New Revision: 184216
> URL:
> Log:
>   partly revert revision 184199, because TDF_NEEDSIGCHK is persitent
>   when thread is in kernel mode, it can cause dead loop, now unlock
>   process lock after acquired sleep queue lock and thread lock to
>   avoid the problem. This means TDF_NEEDSIGCHK and TDF_NEEDSUSPCHK must
>   be set with process lock and thread lock being hold at same time.

You can't unlock the proc lock while holding the thread_lock().  This will 
lead to deadlock due to the way that thread_lock() works.  This is different 
from the rules in 6.x where you could drop a mutex while holding sched_lock.  
You will need to revert this.

John Baldwin

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