> Only for benchmarking? We have done this for years on our production > clusters (and SGI provides a tool this and more to clean up nodes). We > have this in our epilogue so that we can clean out memory on our diskless > nodes so there is nothing stale sitting around that can impact the next > users job.
understood, but how did you decide that was actually a good thing? if two jobs with similar file reference patterns run, for instance, drop_caches will cause quite a bit of additional IO delay. I guess the rationale would also be much clearer for certain workloads, such as big-data reduction jobs, where things like executables would have to be re-fetched, but presumably much larger input data might never be re-referenced by following jobs. it would have to be jobs that have a lot of intra- but not inter-job readonly file re-reference, and where clean-page scavenging is a noticable cost. I'm guessing this may have been a much bigger deal on strongly NUMA machines of a certain era (high-memory ia64 SGI, older kernels). regards, mark. _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
