Arjan van de Ven wrote:
> On Wed, 15 Apr 2009 20:20:32 -0400
> Jeff Garzik <jeff@garzik.org> wrote:
> 
>> The following commit
>>
>>> commit 9710794383ee5008d67f1a6613a4717bf6de47bc
>>> Author: Arjan van de Ven <arjan@linux.intel.com>
>>> Date:   Sun Mar 15 11:11:44 2009 -0700
>>>
>>>     async: remove the temporary (2.6.29) "async is off by default"
>>> code
>> not only changes a default, it completely removes the ability to turn 
>> off async AFAICS.
> 
> this is on the request of Andrew and others who want to be able to use
> these API's (soon) in an "forced offload" scenario. 
> 
>> At present, I need to turn this off to debug boot-time operation.
> 
> can you give some details? Maybe I can help suggest things...

Too much shit is occurring in parallel, which completely obscures the 
operation of the driver I am currently debugging.  A new and unwelcome 
behavior, as it is directly impacting workflow.

Commit 9710794383ee5008d67f1a6613a4717bf6de47bc was fine for the normal 
case, but please have pity on developers!  Just like many multi-threaded 
userland programs have an option to run single-threaded (usually for 
debug purposes), the kernel should have this too.

I need a slowboot option, like the attached patch.

The patch is basically the reverse of your 
9710794383ee5008d67f1a6613a4717bf6de47bc in a different way.

	Jeff