But how can you be sure that this fault handler will be called when the agent crashes On Fri, Nov 21, 2014 at 2:07 PM, Pranay Srivastava <pranjas@xxxxxxxxx> wrote: > Hi Kevin, > > Request you not to top post :-) . > >> On Tue, Nov 18, 2014 at 10:15 AM, Pranay Srivastava <pranjas@xxxxxxxxx> wrote: >>> Hi Kevin >>> >>> >>> >>> >>> On Tue, Nov 18, 2014 at 1:19 PM, Kevin Wilson <wkevils@xxxxxxxxx> wrote: >>>> Hi, >>>> I want to write a kernel module which interacts with a userspace daemon. >>>> There are cases when the userspace daemon can terminate by some signals. >>>> There are also cases where the userspace daemon can crash (in some abnormal >>>> cases). Is there a way that the kernel module will be aware of such >>>> userspace agent crash, in order to reset its state ? >>> >>> Can't you reset it when the daemon is about to be killed from the >>> userspace itself? Depends on how complex/simple you want >>> this but there are several possibilities. Care to tell me how you >>> thought about doing this and where you got stuck? >>> >>> >>>> >>>> Regards, >>>> Kevin >>>> >>>> _______________________________________________ >>>> Kernelnewbies mailing list >>>> Kernelnewbies@xxxxxxxxxxxxxxxxx >>>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >>> >>> >>> Regards >>> -- >>> ---P.K.S >> >>On Fri, Nov 21, 2014 at 4:25 PM, Kevin Wilson <wkevils@xxxxxxxxx> wrote: >> The thing is that crash of the daemon sometimes occur, from this >> reason or other. >> The question is how the kernel module will be aware of such >> userspace agent crash, in order to reset its state ? > > I don't think kernel will know itself. The simplest you can do is put > a fault handler in userspace code > and have it do a write on a sysfs/procfs file or an ioctl or maybe > send signal or enqueue something > to another heartbeat daemon , etc, whatever method seems most > appropriate to you. > > Does this sound useful? > >> >> Regards, >> Kevin >> >> > > > -- > ---P.K.S _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
