Hi, as I recently cleaned up the power events with some format/abi adjustings... I realized that it was rather easy to adjust the stuff in drivers/tools/perf, because there are some nice facilities to query which events are available. I looked at pytimechart, there it's not that nice and convenient would be some kind of version number. pytimechart can parse traces which are simply copied away from /sys/kernel/debug/trace and to check for available events and their format, one would have to do a separate, ugly to implement, iteration of parsing. Would it make sense to introduce a trace ABI version number? It would be enough to increase it by one every time any event (don't know about other perf facilities) is added, removed or modified. Ideally the modifications are tracked with a short description in a file like Documentation/trace/format.changes Untested, but the patch at the end should simply add a version number on top of /sys/kernel/debug/trace file While this should be enough for the kernel, perf record would need to include it into it's binary perf.data format as well? Then userspace apps could easily test whether supported events would be included at all, whether only a subset of supported events were made available and which format they have. Does this make sense? Thanks, Thomas -- To unsubscribe from this list: send the line "unsubscribe linux-trace-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html