1 Dec
2017
1 Dec
'17
10:18 p.m.
On Fri, Dec 01, 2017 at 11:11:56AM -0500, Clem Cole wrote:
It's hard because if I/O (like DMA) is in
progress, what are the proper
semantics to exit/roll back? When do you stop the transfer and what
happens. When doing direct to/from disk (like a in a real-time system),
this can get tricky.
So at first blush, what it seems like is you need a barrier to starting more
DMA's. You take the signal, the signal changes state to say to the I/O
system "finish what you are doing but then no more".
Or what you do is kill the process, tear down all of the pages except those
that are locked for I/O, leave those in the process and wait for the I/O to
get done. That might be simpler.