* Davidlohr Bueso <davidlohr@xxxxxx> wrote: > > Or is access to varied in the Oracle case that it's missing the cache > > all the time, because the rbtree causes many cachemisses as the > > separate nodes are accessed during an rb-walk? > > Similar to get_cycles(), is there anyway to quickly measure the amount > of executed instructions? Getting the IPC for the mmap_cache (this of > course is constant) and the treewalk could give us a nice overview of > the function's cost. I was thinking of stealing some perf-stat > functionality for this but didn't get around to it. Hopefully there's an > easier way... There's no such easy method I'm afraid (Frederic's probe based trigger facility will give us that and more - but it's not ready yet) - but you could try profiling the workload for significant cache-misses: perf record -e cache-misses ... I _think_ if it's really catastrophic cache-misses then the rbtree walk should light up on the perf radar like crazy. Thanks, Ingo -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>