* Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx> wrote: > I guess the second reason is why the stap takes so long time to set > probes. stap tries to register kprobes without disabled flag, that > means we enables thousands of probes (overheads). > > So the similar thing happens when we enables events as below; > > # for i in /sys/kernel/debug/tracing/events/kprobes/* ; do date; echo 1 > $i; done > Wed Jan 29 10:44:50 UTC 2014 > ... > > I tried it and canceled after 4 min passed. It enabled about 17k > events and slowed down my system very much(I almost got hang check > timer). Ok, I guess that's the slowdown bug that Frank reported. > I think we should have some performance statistics (hit count?) and > if it goes over a threshold, we should stop enabling other events. That really feels like a hack. How about fixing the root cause? Does the enabling of all probes have to be so slow? Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
