On Thu, Dec 13, 2018 at 10:21:26AM -0300, Arnaldo Carvalho de Melo wrote: [...]
> > > commit 148068b45fe2e93b19c06cfc1140ea12ca72eb59 > > > Author: Leo Yan <leo....@linaro.org> > > > Date: Tue Dec 11 15:38:26 2018 +0800 > > > > > > perf cs-etm: Treat NO_SYNC element as trace discontinuity > > > > > > The CoreSight tracer driver might insert a barrier packets between > > packet > > I'll remove the 'a' instead, ok? Yeah. > > > different buffers, thus the decoder can spot the boundaries based on > > > the > > > barrier packet; it is possible for the decoder to hit a barrier packet > > > and emit a NO_SYNC element, then the decoder will find a periodic > > > synchronisation point inside that next trace block that starts the > > > trace > > > again but does not have the TRACE_ON element as indicator - usually > > > because this trace block has wrapped the buffer so we have lost the > > > original point when the trace was enabled. > > > > > > In the first case it causes the insertion of a > > > OCSD_GEN_TRC_ELEM_NO_SYNC > > former > > > in the middle of the the tracing stream, but as we were npt handling > > > the > > not > > > NO_SYNC element properly which ends up making users miss the > > > discontinuity indication"? > > s/?/. > > > > Thanks a lot for helping. If you prefer me to resend the patch set, > > also let me know. > > I can fix it, here. Thanks a lot! > > > Though OCSD_GEN_TRC_ELEM_NO_SYNC is different from CS_ETM_TRACE_ON > > > when > > > output from the decoder, both indicate that the trace data is > > > discontinuous; this patch treats OCSD_GEN_TRC_ELEM_NO_SYNC as a trace > > > discontinuity and generates a CS_ETM_DISCONTINUITY packet for it, so > > > cs-etm can handle the discontinuity for this case, finally it saves > > > the > > > last trace data for the previous trace block and restart samples for > > > the > > > new block. > > > > > > Signed-off-by: Leo Yan <leo....@linaro.org> > > > Reviewed-by: Mathieu Poirier <mathieu.poir...@linaro.org> > > > Cc: Alexander Shishkin <alexander.shish...@linux.intel.com> > > > Cc: Jiri Olsa <jo...@redhat.com> > > > Cc: Mike Leach <mike.le...@linaro.org> > > > Cc: Namhyung Kim <namhy...@kernel.org> > > > Cc: Robert Walker <robert.wal...@arm.com> > > > Cc: coresight ml <coresi...@lists.linaro.org> > > > Cc: linux-arm-ker...@lists.infradead.org > > > Link: > > > http://lkml.kernel.org/r/1544513908-16805-7-git-send-email-leo....@linaro.org > > > Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> > > > > > > diff --git a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c > > > b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c > > > index 1039f364f4cc..bee026e76a4c 100644 > > > --- a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c > > > +++ b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c > > > @@ -410,7 +410,6 @@ static ocsd_datapath_resp_t > > > cs_etm_decoder__gen_trace_elem_printer( > > > case OCSD_GEN_TRC_ELEM_UNKNOWN: > > > break; > > > case OCSD_GEN_TRC_ELEM_NO_SYNC: > > > - break; > > > case OCSD_GEN_TRC_ELEM_TRACE_ON: > > > resp = cs_etm_decoder__buffer_discontinuity(decoder, > > > trace_chan_id); > > > > > > > > -- > > - Arnaldo
