* Namhyung Kim <namhy...@kernel.org> wrote: > > A couple of details: > > > > 1) > > > > This is pretty close to SysProf output, right? So why not use the > > well-known SysProf naming and call the first column 'self' and the > > second column 'total'? I think those names are pretty intuitive and > > it would help people who come from SysProf over to perf. > > Okay, I can do it. (Although sysprof seems to call it 'cumulative' > rather than 'total' - but I think the 'total' is better since it's > simpler and shorter.)
So sysprof-1.2 has the following two windows: 'functions', with 'self' and 'total' fields 'descendants', with 'self' and 'cumulative' fields 'descendants' appears to be similar to the perf 'dso' concept. > > 2) > > > > Is it possible to configure the default 'report -g' style, so that > > people who'd like to use it all the time don't have to type '-g > > cumulative' all the time? > > Hmm.. maybe I can add support for the 'report.call-graph' config option. If we display your new 'total' field by default then it's not as pressing to me :) > > 3) > > > > I'd even argue that we enable this reporting feature by default, if > > a data file includes call-chain data: the first column will still > > show the well-known percentage that perf report produces today, the > > second column will be a new feature in essence. > > > > The only open question would be, by which column should we sort: > > 'sysprof style' sorts by 'total', 'perf style' sorts by 'self'. > > Agreed? > > Right, I defaulted to go by 'total'. But we can add an option for > it. The purpose would be to allow people to do old-style 'sort by function overhead' output, while still seeing the 'total' field as well. Btw., if anyone is interested in improving the GTK front-end, it would be _really_ nice if it had a 'start profiling' button like sysprof has today, with a 'samples' field showing the current number of samples. (We could even improve upon sysprof by adding 'stop' functionality as well ;-) A bit like perf top, except the reporting session is hidden until the user actively requests the profile. Maybe it could even be called a gtk version of 'perf top', with a button to start/stop collection, with another button to activate/deactivate reporting output, and yet another button to reset the profiling buffer. With that feature set perf would be a ready sysprof workflow replacement I think. (I've Cc:-ed Pekka, just in case! :-) > > 4) > > > > This is not directly related to the new feature you added: > > call-graph profiling still takes quite a bit of time. It might > > make sense to save the ordered histogram to a perf.data.ordered > > file, so that repeat invocations of 'perf report' don't have to > > recalculate everything again and again? > > > > This file would be maintained transparently and would only be > > re-created when the perf.data file changes, or something like > > that. > > Hmm.. good idea. We may discuss it along with Jiri's multiple > file storage patches. I haven't had a time to review - maybe next > week. So Arnaldo tells me that with your and Frederic's latest callgraph-speedup patches the parsing of perf.data got _really_ fast, so maybe my performance complaint is moot and we should delay complicating the primary perf.data file model with a 'cache' until your patches are in and we see the full impact. Thanks, Ingo -- 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/