What was the performance of the multiprocessor system?
For the PDP-11/74, configured with four processors and all of them running, about three times that of the 11/70. Not much competition for an 11/780, actually. What metric was used is unknown. Source: The Big Book of RSX Applications, Volume II, Appendix B How did the multiprocessor system handle CPU crashes? Surprisingly enough, very badly. When one CPU crashed, all the CPUs crashed. “The philosophy of the 11/74 was high availability, not high reliability. As such, from a philosophical viewpoint, we wanted crash dumps of all the CPUs to catch software problems.” “Pragmatically speaking, continuing would be difficult. The crashing CPU is in the kernel, owning at least $EXECL in all likelihood, and perhaps some other spin locks. Of course, any lock it owned was owned to protect an atomic transaction, and the crash caused some decay.” “The fork list may not be intact, the Pool may not be intact, device states may be inconsistent, the context of the running task on the crashed CPU (which c
For the PDP-11/74, configured with four processors and all of them running, about three times that of the 11/70. (Not much competition for an 11/780, actually.) What metric was used is unknown. Source: The Big Book of RSX Applications, Volume II, Appendix B How did the multiprocessor system handle CPU crashes? Surprisingly enough, very badly. When one CPU crashed, all the CPUs crashed. “The philosophy of the 11/74 was high availability, not high reliability. As such, from a philosophical viewpoint, we wanted crash dumps of all the CPUs to catch software problems. “Pragmatically speaking, continuing would be difficult. The crashing CPU is in the kernel, owning at least $EXECL in all likelihood, and perhaps some other spin locks. Of course, any lock it owned was owned to protect an atomic transaction, and the crash caused some decay.” “The fork list may not be intact, the Pool may not be intact, device states may be inconsistent, the context of the running task on the crashed CPU (which
