🚀 go-pugleaf

In article <1991Apr4.035548.25439@m.cs.uiuc.edu> rchen@m.cs.uiuc.edu (Rong Chen) writes:
:dswartz@bigbootay.sw.stratus.com (Dan Swartzendruber) writes:
::Interrupts must be masked first, since otherwise you have a race condition
::where the lock is acquired on call-side and an interrupt comes in before
::the spl call.  If the interrupt handler tries to acquire the same lock,
::you're stuck, since the only code which can release the lock is the same
::thread which is now servicing the interrupt.
:
:Why do we want the interrupt handlers to acquire locks?  I thought
:the interrupt handlers should always be executed from begin to end
:without any complications.  Usually the handlers will only change
:some volatile data structures in the kernel space.  Shouldn't we
:limit interrupt interface only between kernel and hardware, and
:spin-locks only among kernel objects?
:

Just out of curiosity, how do you suggest that the interrupt handler
"change the volatile structure" in kernel space in a multiprocessor
environment when there are other threads of control trying to do the
same thing?

:-Rong Chen
: Department of Computer Science
: University of Illinois at Urbana-Champaign


--

Dan S.