Christopher Friedt wrote: > Hi, > > I'm currently writing my own light-weight DLM and my manager says that > its taking too long and I should look at using something already out there. > > I need to lock a shared resource in a building with nodes on the same > LAN - specifically I'm locking a radio frequency (truly a shared > resource, in every sense of the word). > > Network latency can be assumed to be very small. > > Only one node is allowed to transmit / receive on the radio frequency at > one time. > > The article on KernelTrap[1] pointed me here, and I just wanted to ask a > few questions. > > - is DLM suitable for embedded systems ? > - what are the major changes / additions, etc to the linux kernel ? > - does it patch to the latest linux kernel? > - does it patch to the 2.4 kernels? > - are any user-space tools necessary? You'll need libdlm, which is included in the cluster suite CVS or tarballs at http://sourceware.org/cluster/ It uses a device node interface to communication with the DLM in the kernel. > - how does an application interface to DLM ? (device node? etc) There is a VMS-Style call interface that provides full access to all of the facilities. there's also a simpler on for basic lock/unlock requests. That is provided by libdlm. Documentation here: http://people.redhat.com/pcaulfie/docs/rhdlmbook.pdf > - to the best of your knowlege, would DLM be suitable for the scenario I > described above? Hard to tell to be perfectly honest. The major user of the DLM is GFS, a cluster filesystem though it is designed to be a generic DLM. Patrick -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
