(2014/11/07 19:51), Hemant Kumar wrote: >> >> File Format >> =========== >> All the cache files are placed under ~/.debug/ by default. >> The paths of buildid cache of binary/symbols are not changed. >> >> The SDT/probe caches are placed under the >> ~/.debug/.probes/path/to/bin/bu/ildid >> and that is linked to ~/.debug/.probes/.buildid/bu/ildid >> # To avoid conflict with files under /probes/*, I picked up .probes/. >> >> This SDT/probe caches contain probe-definitions as following format. >> ---- >> #buildid:BUILDID >> #path:PATH >> p:%PROVIDER/EVENT PATH:OFFSET [ARGS] > > I think this format isn't accepted by the uprobe_events file (because of > the '%') if we want to cat and grep into uprobe_events file directly. > Although, in case of perf record, we can process it to remove '%' and > then write into uprobe_events file. And, '%' is required as a flag for > the SDT entries.
Ah, right... > So, either we can modify the uprobe_events file to ignore '%' in the > event group name (with an additional patch in the SDT series) or we can > leave it to the user to write a script which can do some processing to > remove '%' and then echo it to uprobe_events file. > What would you think? Hmm, ok. I think we can unify SDT and probe cache as just an cached event. So replacing % with probe_ prefix is OK I think. What I mean is if you add a file to cache, perf adds SDTs in the file, and if you add a file with some expressions, like '* $params', perf also adds probe caches. And you can use both events for not only tracing but also profiling. e.g. perf cache --add /bin/foo # add foo's SDTs perf cache --add /bin/foo --probe 'foofunc $params' # add a probe cache for foofunc perf record -e %foo:sdtevent -e %foo:foofunc ... # we can record both SDT and cache So, % prefix means "recall cached probe/sdt events to record if needed". If you already set up the probe-events on those, you don't need % as below. perf probe --add "%foo:sdtevent" # add new probe_foo:sdtevent for %foo:sdtevent perf record -e probe_foo:sdtevent ... Note that to avoid crash with existing event groups, we'll add "probe_" prefix for cached events. Thank you, -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Research Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu...@hitachi.com -- 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/
