Hi Felipe, On 17 May 2017 at 16:08, Felipe Balbi <felipe.ba...@linux.intel.com> wrote: > > Hi Chunyan, > > When you wrote your patchset to provide ftrace exports, why did you > choose to export only function trace? Why not tracepoints,
In fact, I tried submitting patches[1] to do exporting tracepoint to STM, but Ingo and Steven commented that would introduce certain amount of overhead, and that was not acceptable. I also used 'benchmark_event' to see the additional overhead caused by printing tracepoint message to STM. I cannot remember the exact data though, the increased time consuming indeed was non-ignorable. So at the end I gave up that idea, and later on switched to the way of implementation you see in the kernel now. > function_graph, hwlat, irqsoff and all the other possibilities? I haven't thought about these clear enough :) Any suggestion? Thanks, Chunyan [1] https://lkml.org/lkml/2015/7/7/230 > > Is there an underlying reason why you chose to export only function > trace? > > Thanks > > -- > balbi
