CAM rescanner thread?

[Scott Long]

mjacob at freebsd.org wrote:
> 
> 
> On Fri, 5 Jan 2007, Scott Long wrote:
> 
>> mjacob at freebsd.org wrote:
>>>
>>> Opinions? Seems to do what *I* want for automatically attaching 
>>> devices for mpt or isp when they appear on the fabric. All you have 
>>> to do is
>>> alloc a ccb && a path and call xpt_rescan.
>>
>> Why do you need a separate thread for this?  Many other drivers 
>> already handle this just fine.
> 
> In CAM?
> 
> I did try doing it without a thread and had all sorts of problems that 
> led to panics. I suppose I could try and fix that, but it's also true 
> that notification that things have changed is almost certainly on an 
> ithread and that the begin of a scan starts a heck of a lot of work 
> before returning.
> 
> D'ya think it's that crucial other than just another proc slot?
> 
> -matt
> 

Ok, I see what you're saying.  What I think needs to ultimately happen 
is for the entire probe code to go into a thread.  I've tried this a
couple of times, but have been caught up in trying to separate out the
SPI and non-SPI bits of it.  Your patch is looks to be a good start at
the more simple approach.

Scott