Messages in this thread | | | Date | Fri, 22 May 2009 16:52:23 +0300 | Subject | Re: How to tell whether a struct file is held by a process? | From | Pantelis Koukousoulas <> |
| |
On Fri, May 22, 2009 at 4:43 PM, Alan Cox <alan@lxorguk.ukuu.org.uk> wrote: >> Suppose a device needs a reset as part of its init sequence (a whole lot >> of them do, this is not purely hypothetical). Then a different process may >> get to operate the device before and after the reset and hilarity may result >> from that. > > Thats surely up to you to get your lock file usage right. The kernel > isn't there to play mother to crap programming.
Who is "me" in this case? Assuming that those writing the userspace programs are cooperative though, I agree. We can declare that whatever program does not play by the (userspace locking) rules is crap and either fix it (if open source) or refuse to install it / complain (if closed source).
> >> So, if there is a clean / acceptable way to handle the reset issue in userspace > > Firstly can you explain *why* you think there is a problem ? >
I admit this could be a bias from the way I imagined the whole thing to work before this discussion. I think I can see how a userspace locking scheme based on port numbers could avoid also the reset problem.
Thanks, Pantelis
| |