cvs commit: src/sys/kern subr_sleepqueue.c

[Jeff Roberson]

On Wed, 19 Mar 2008, David Xu wrote:

> Jeff Roberson wrote:
>> jeff        2008-03-19 07:35:14 UTC
>>
>>   FreeBSD src repository
>>
>>   Modified files:
>>     sys/kern             subr_sleepqueue.c   Log:
>>    - At the top of sleepq_catch_signals() lock the thread and check 
>> TDF_NEEDSIGCHK
>>      before doing the very expensive cursig() and related locking. 
>> NEEDSIGCHK
>>      is updated whenever our signal mask change or when a signal is 
>> delivered and
>>      should be sufficient to avoid the more expensive tests.  This 
>> eliminates
>>      another source of PROC_LOCK contention in multithreaded programs.
>>     Revision  Changes    Path
>>   1.50      +12 -4     src/sys/kern/subr_sleepqueue.c
>> 
>
> This may break process suspension, a more completed patch is here: (though it 
> is outdated):
>
> http://people.freebsd.org/~davidxu/patch/PCATCH_optimize.patch
>
> In one word, process suspending may be in progress, and the thread
> should check it.

Thanks Xu.  I will add your NEEDSUSPCHECK flag and check that as well.

>
> Regards,
> David Xu
>
>