Hi - > > 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.
It could be, but it feels a bit different. In my testing from December, it's as though it wasn't the activated probes *hitting* that were associated with the slowdown, but them merely being activated. It was as though something with the kprobes/ftrace probe-registration code performed a lot more work than it did longer ago. (One way to test this could be to be more careful in the selection of kprobes being enabled. For examle, emplace thousands, but only unused loaded modules.) I'm sorry I didn't get time to investigate further. - FChE -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
