Messages in this thread | | | Date | Tue, 3 Aug 2021 10:24:09 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [RFC PATCH 6/6] perf cs-etm: Add warnings for missing DSOs |
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Em Mon, Aug 02, 2021 at 11:41:45PM +0800, Leo Yan escreveu: > On Thu, Jul 29, 2021 at 04:58:05PM +0100, James Clark wrote: > > Currently decode will silently fail if no binary data is available for > > the decode. This is made worse if only partial data is available because > > the decode will appear to work, but any trace from that missing DSO will > > silently not be generated. > > > > Add a UI popup once if there is any data missing, and then warn in the > > bottom left for each individual DSO that's missing. > > > > Signed-off-by: James Clark <james.clark@arm.com> > > --- > > tools/perf/util/cs-etm.c | 10 +++++++++- > > 1 file changed, 9 insertions(+), 1 deletion(-) > > > > diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c > > index 32ad92d3e454..e6851260d059 100644 > > --- a/tools/perf/util/cs-etm.c > > +++ b/tools/perf/util/cs-etm.c > > @@ -746,8 +746,16 @@ static u32 cs_etm__mem_access(struct cs_etm_queue *etmq, u8 trace_chan_id, > > > > len = dso__data_read_offset(al.map->dso, machine, offset, buffer, size); > > > > - if (len <= 0) > > + if (len <= 0) { > > + ui__warning_once("CS ETM Trace: Missing DSO. Use 'perf archive' to export data from the traced system.\n"); > > + if (!al.map->dso->auxtrace_warned) { > > + pr_err("CS ETM Trace: Debug data not found for address %#"PRIx64" in %s\n", > > + address, > > + al.map->dso->long_name ? al.map->dso->long_name : "Unknown"); > > + al.map->dso->auxtrace_warned = true; > > + } > > This is very useful. > > Just one comment: in particularly if the perf fails to find the kernel > symbols, the user needs to enable config "CONFIG_PROC_KCORE=y" or > specify option "-k /path/to/vmlinux". In this case, using 'perf > archive' is not helpful. So I think the UI warning can be imporved > like: > > ui__warning_once("CS ETM Trace: Missing DSO. Use 'perf archive' to export data from the traced system.\n" > " Enable CONFIG_PROC_KCORE or use option '-k /path/to/vmlinux' for kernel symbols\n");
one can also use debuginfod-client, which, as time passes, probably will be the main way of finding DSOs now that we have build-ids in PERF_RECORD_MMAP2 and debuginfod servers such as:
export DEBUGINFOD_URLS=https://debuginfod.fedoraproject.org/
https://fedoraproject.org/wiki/Debuginfod
> With this improvement, the patch looks good to me: > > Reviewed-by: Leo Yan <leo.yan@linaro.org>
Does this apply to the other 5 patches in this series?
- Arnaldo
> > return 0; > > + } > > > > return len; > > } > > -- > > 2.28.0 > >
--
- Arnaldo
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