interrupt handlers in -current

[John Baldwin]

On 06-Jun-2003 M. Warner Losh wrote:
> In message: <XFMail.20030606002657.dmlb at dmlb.org>
>             Duncan Barclay <dmlb at dmlb.org> writes:
>: 
>: On 05-Jun-2003 M. Warner Losh wrote:
>: > In message: <XFMail.20030605220236.dmlb at dmlb.org>
>: >             Duncan Barclay <dmlb at dmlb.org> writes:
>: >: This is more of a confirmation of my understanding than anything else.
>: >: In -current, should an interrupt thread be created you set up an interrupt
>: >: handler? If so, then I'd better check my code because I haven't got one!
>: > 
>: > No.  Just because we handle interrupts in a thread doesn't mean client
>: > devices need to create a thread.  The thread is creted automatically
>: > and the routine passed to bus_setup_intr() is then called when an
>: > interrupt happens.
>: 
>: Rereading what I wrote, I might have mistyped and asked the wrong question.
>: 
>: I think what you saying is that bus_setup_intr() doesn't create the thread,
>: (in the sense of it appear in ps -ax?)
>: but a thread is created automatically when the first interrupt occurs?
> 
> The thread is created right away.  However, if this interrupt is
> shared with another device, you'll see seomthing like:
> 
> root        23  0.0  0.0     0   12  ??  WL   11:35AM   0:04.24  (irq10: cbb0 cbb1++)
> 
> which says taht cbb0 and cbb1 (and others) share irq10.

The thread is created right away, but I think KSE broke ps/top in
that they don't show new processes anymore that haven't run yet.  This
is definitely a bug in the kernel.

-- 

John Baldwin <jhb at FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve!"  -  http://www.FreeBSD.org/