Re: sio: lots of silo overflows on Asus K8V with Moxa Smartio C104H/PCI

On Mon, 3 May 2004, Robert Watson wrote:

> On Mon, 3 May 2004, Bruce Evans wrote:
> > Unsafe.  SWIs are wrapped by Giant unless they are created using
> > swi_add(... INTR_MPSAFE ...).  There are 26 calls to swi_add() in the
> > tree, and the slow progress of Giant removal is shown by only 3 of
> > these using INTR_MPSAFE.  The ones in sio are not in the 3.  The 3
> > are all just for multiplexors that push down deciding whether to use
> > Giant to lower layers:
>
> Actually, it's a little more complex than that: most of the callers if
> swi_add() with INTR_MPSAFE are actually via bus_setup_intr() which accepts
> similar flags.  You'll find that a much larger number of interrupts are
> capable of running mpsafe if you search for that.  Also, unless

Um, bus_setup_intr() is for hardware interrupts.  It doesn't call
swi_add(), since swi_add() is for software interrupts.  Hardware
interrupts were not being discussed here.  You may be thinging of
ithread_add_handler() which is a common core for swi_add() and
bus_setup_intr().

BTW, there are about 34 broken drivers that use
BUS_SETUP_INTR(device_get_parent(...), ...) instead of bus_setup_interrupt().
This just evades printing of the FAST/GIANT-LOCKED/MPSAFE boot message.
BUS_SETUP_INTR() seems to be needed in only 10 files.

Bruce