> -----Original Message----- > From: Arnaldo Carvalho de Melo [mailto:a...@kernel.org] > Sent: Friday, October 02, 2015 4:40 PM > To: Liang, Kan > Cc: Jiri Olsa; jo...@kernel.org; namhy...@kernel.org; a...@linux.intel.com; > linux-kernel@vger.kernel.org; Stephane Eranian > Subject: Re: [PATCH 1/1] perf,stat: reduce interval-print to 10ms > > Em Fri, Oct 02, 2015 at 08:22:06PM +0000, Liang, Kan escreveu: > > > > > + if (interval < 10) { > > > > > + pr_err("print interval must be >= 10ms\n"); > > > > > + parse_options_usage(stat_usage, options, > "I", 1); > > > > > + goto out; > > > > > + } else > > > > > + pr_warning("print interval < 100ms. " > > > > > + "The overhead percentage could > be high > > > in some cases. " > > > > > + "Please proceed with caution.\n"); > > > > > > > > with '-I' 10 this warning flies away quite fast ;-) > > > > > > > > I guess it's better than nothing, and I'm not sure about putting > > > > some sleep after that warning.. > > > > > > > > Acked-by: Jiri Olsa <jo...@kernel.org> > > > > > > Right, this should appear in the man page as well, I added the patch > > > below, we could also print that warning when the workload ends. > > > OK. We can print the warning message again at the end as the patch > below. > > > > +++ b/tools/perf/builtin-stat.c > > @@ -1377,6 +1377,11 @@ int cmd_stat(int argc, const char **argv, const > char *prefix __maybe_unused) > > if (!forever && status != -1 && !interval) > > print_counters(NULL, argc, argv); > > > > + if (interval && interval < 100) > > + pr_warning("print interval < 100ms. " > > + "The overhead percentage could be high in some > cases. " > > + "Please proceed with caution.\n"); > > Yeah, something like that, but the warning then becomes strange, > "proceed"? I guess that something like: > > pr_warning("print interval < 100ms. " > "The overhead percentage could have been high. > " > "Take that into account when interpreting the > these numbers.\n"); > > Right?
Yes. Thanks, Kan > > - Arnaldo > > > + > > perf_evlist__free_stats(evsel_list); > > out: > > perf_evlist__delete(evsel_list); -- 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/
