| Message ID | 1544513908-16805-7-git-send-email-leo.yan@linaro.org |
|---|---|
| State | Accepted |
| Commit | 37bb37168dc1b1f5e3ac791aeecd14ef980764fd |
| Headers | show |
| Series | perf cs-etm: Correct packets handling | expand |
Em Tue, Dec 11, 2018 at 03:38:26PM +0800, Leo Yan escreveu: > CoreSight tracer driver might insert barrier packet between different > buffers, thus the decoder can spot the boundaries based on the barrier > packet; the decoder is possible 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 trace again but does not > have the TRACE_ON element as indicator - usually because this block of > trace has wrapped the buffer so we have lost the original point that > trace was enabled. > > In upper case, it results in the trace stream only inserts the > OCSD_GEN_TRC_ELEM_NO_SYNC element in the middle of tracing stream, but > we don't handle NO_SYNC element properly and at the end users miss to > see the info for trace discontinuity. "In upper case"? Maybe: In the former case it causes the insertion of a OCSD_GEN_TRC_ELEM_NO_SYNC in the middle of the the tracing stream, but as we were npt handling the NO_SYNC element properly which ends up making users miss the discontinuity indication"? > Though OCSD_GEN_TRC_ELEM_NO_SYNC is different from CS_ETM_TRACE_ON when > output from the decoder, but both of them indicate the trace data is can we remove the "but" and "of them" (redundant) above? > discontinuous; this patch treats OCSD_GEN_TRC_ELEM_NO_SYNC as trace a > discontinuity and generates CS_ETM_DISCONTINUITY packet for it, so > cs-etm can handle discontinuity for this case, finally it saves the last it (way too many "discontinuity") > trace data for previous trace block and restart samples for new block. > > Signed-off-by: Leo Yan <leo.yan@linaro.org> > Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> > Cc: Mike Leach <mike.leach@linaro.org> > Cc: Robert Walker <robert.walker@arm.com> > --- > tools/perf/util/cs-etm-decoder/cs-etm-decoder.c | 1 - > 1 file changed, 1 deletion(-) > > 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 1039f364..bee026e 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); > -- > 2.7.4 -- - Arnaldo
Em Thu, Dec 13, 2018 at 09:38:54AM -0300, Arnaldo Carvalho de Melo escreveu: > Em Tue, Dec 11, 2018 at 03:38:26PM +0800, Leo Yan escreveu: > > CoreSight tracer driver might insert barrier packet between different > > buffers, thus the decoder can spot the boundaries based on the barrier > > packet; the decoder is possible 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 trace again but does not > > have the TRACE_ON element as indicator - usually because this block of > > trace has wrapped the buffer so we have lost the original point that > > trace was enabled. > > > > In upper case, it results in the trace stream only inserts the > > OCSD_GEN_TRC_ELEM_NO_SYNC element in the middle of tracing stream, but > > we don't handle NO_SYNC element properly and at the end users miss to > > see the info for trace discontinuity. > > > "In upper case"? Maybe: > > In the former case it causes the insertion of a OCSD_GEN_TRC_ELEM_NO_SYNC > in the middle of the the tracing stream, but as we were npt handling the > NO_SYNC element properly which ends up making users miss the > discontinuity indication"? > > Though OCSD_GEN_TRC_ELEM_NO_SYNC is different from CS_ETM_TRACE_ON when > > output from the decoder, but both of them indicate the trace data is > > can we remove the "but" and "of them" (redundant) above? > > > discontinuous; this patch treats OCSD_GEN_TRC_ELEM_NO_SYNC as trace > a > > discontinuity and generates CS_ETM_DISCONTINUITY packet for it, so > > cs-etm can handle discontinuity for this case, finally it saves the last > it (way too many "discontinuity") > > trace data for previous trace block and restart samples for new block. I've tentatively done those changes (and a few more) in my local branch, resulting in the wording below, plese let me know if you are ok with it: commit 148068b45fe2e93b19c06cfc1140ea12ca72eb59 Author: Leo Yan <leo.yan@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 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 in the middle of the the tracing stream, but as we were npt handling the NO_SYNC element properly which ends up making users miss the discontinuity indication"? 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.yan@linaro.org> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mike Leach <mike.leach@linaro.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Robert Walker <robert.walker@arm.com> Cc: coresight ml <coresight@lists.linaro.org> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1544513908-16805-7-git-send-email-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo <acme@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);
Hi Arnaldo, On Thu, Dec 13, 2018 at 09:41:54AM -0300, Arnaldo Carvalho de Melo wrote: > Em Thu, Dec 13, 2018 at 09:38:54AM -0300, Arnaldo Carvalho de Melo escreveu: > > Em Tue, Dec 11, 2018 at 03:38:26PM +0800, Leo Yan escreveu: > > > CoreSight tracer driver might insert barrier packet between different > > > buffers, thus the decoder can spot the boundaries based on the barrier > > > packet; the decoder is possible 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 trace again but does not > > > have the TRACE_ON element as indicator - usually because this block of > > > trace has wrapped the buffer so we have lost the original point that > > > trace was enabled. > > > > > > In upper case, it results in the trace stream only inserts the > > > OCSD_GEN_TRC_ELEM_NO_SYNC element in the middle of tracing stream, but > > > we don't handle NO_SYNC element properly and at the end users miss to > > > see the info for trace discontinuity. > > > > > > "In upper case"? Maybe: > > > > In the former case it causes the insertion of a OCSD_GEN_TRC_ELEM_NO_SYNC > > in the middle of the the tracing stream, but as we were npt handling the > > NO_SYNC element properly which ends up making users miss the > > discontinuity indication"? > > > > Though OCSD_GEN_TRC_ELEM_NO_SYNC is different from CS_ETM_TRACE_ON when > > > output from the decoder, but both of them indicate the trace data is > > > > can we remove the "but" and "of them" (redundant) above? > > > > > discontinuous; this patch treats OCSD_GEN_TRC_ELEM_NO_SYNC as trace > > a > > > discontinuity and generates CS_ETM_DISCONTINUITY packet for it, so > > > cs-etm can handle discontinuity for this case, finally it saves the last > > it (way too many "discontinuity") > > > trace data for previous trace block and restart samples for new block. > > I've tentatively done those changes (and a few more) in my local branch, > resulting in the wording below, plese let me know if you are ok with it: Very appreciate your helping. Please see some minor typos in below commit: > commit 148068b45fe2e93b19c06cfc1140ea12ca72eb59 > Author: Leo Yan <leo.yan@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 > 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. > 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.yan@linaro.org> > Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> > Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> > Cc: Jiri Olsa <jolsa@redhat.com> > Cc: Mike Leach <mike.leach@linaro.org> > Cc: Namhyung Kim <namhyung@kernel.org> > Cc: Robert Walker <robert.walker@arm.com> > Cc: coresight ml <coresight@lists.linaro.org> > Cc: linux-arm-kernel@lists.infradead.org > Link: http://lkml.kernel.org/r/1544513908-16805-7-git-send-email-leo.yan@linaro.org > Signed-off-by: Arnaldo Carvalho de Melo <acme@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); > >
Em Thu, Dec 13, 2018 at 09:09:49PM +0800, leo.yan@linaro.org escreveu: > Hi Arnaldo, > > On Thu, Dec 13, 2018 at 09:41:54AM -0300, Arnaldo Carvalho de Melo wrote: > > Em Thu, Dec 13, 2018 at 09:38:54AM -0300, Arnaldo Carvalho de Melo escreveu: > > > Em Tue, Dec 11, 2018 at 03:38:26PM +0800, Leo Yan escreveu: > > > > CoreSight tracer driver might insert barrier packet between different > > > > buffers, thus the decoder can spot the boundaries based on the barrier > > > > packet; the decoder is possible 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 trace again but does not > > > > have the TRACE_ON element as indicator - usually because this block of > > > > trace has wrapped the buffer so we have lost the original point that > > > > trace was enabled. > > > > > > > > In upper case, it results in the trace stream only inserts the > > > > OCSD_GEN_TRC_ELEM_NO_SYNC element in the middle of tracing stream, but > > > > we don't handle NO_SYNC element properly and at the end users miss to > > > > see the info for trace discontinuity. > > > > > > > > > "In upper case"? Maybe: > > > > > > In the former case it causes the insertion of a OCSD_GEN_TRC_ELEM_NO_SYNC > > > in the middle of the the tracing stream, but as we were npt handling the > > > NO_SYNC element properly which ends up making users miss the > > > discontinuity indication"? > > > > > > Though OCSD_GEN_TRC_ELEM_NO_SYNC is different from CS_ETM_TRACE_ON when > > > > output from the decoder, but both of them indicate the trace data is > > > > > > can we remove the "but" and "of them" (redundant) above? > > > > > > > discontinuous; this patch treats OCSD_GEN_TRC_ELEM_NO_SYNC as trace > > > a > > > > discontinuity and generates CS_ETM_DISCONTINUITY packet for it, so > > > > cs-etm can handle discontinuity for this case, finally it saves the last > > > it (way too many "discontinuity") > > > > trace data for previous trace block and restart samples for new block. > > > > I've tentatively done those changes (and a few more) in my local branch, > > resulting in the wording below, plese let me know if you are ok with it: > > Very appreciate your helping. Please see some minor typos in below > commit: > > > commit 148068b45fe2e93b19c06cfc1140ea12ca72eb59 > > Author: Leo Yan <leo.yan@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? > > 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. > > 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.yan@linaro.org> > > Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> > > Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> > > Cc: Jiri Olsa <jolsa@redhat.com> > > Cc: Mike Leach <mike.leach@linaro.org> > > Cc: Namhyung Kim <namhyung@kernel.org> > > Cc: Robert Walker <robert.walker@arm.com> > > Cc: coresight ml <coresight@lists.linaro.org> > > Cc: linux-arm-kernel@lists.infradead.org > > Link: http://lkml.kernel.org/r/1544513908-16805-7-git-send-email-leo.yan@linaro.org > > Signed-off-by: Arnaldo Carvalho de Melo <acme@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
On Thu, Dec 13, 2018 at 10:21:26AM -0300, Arnaldo Carvalho de Melo wrote: [...] > > > commit 148068b45fe2e93b19c06cfc1140ea12ca72eb59 > > > Author: Leo Yan <leo.yan@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.yan@linaro.org> > > > Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> > > > Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> > > > Cc: Jiri Olsa <jolsa@redhat.com> > > > Cc: Mike Leach <mike.leach@linaro.org> > > > Cc: Namhyung Kim <namhyung@kernel.org> > > > Cc: Robert Walker <robert.walker@arm.com> > > > Cc: coresight ml <coresight@lists.linaro.org> > > > Cc: linux-arm-kernel@lists.infradead.org > > > Link: http://lkml.kernel.org/r/1544513908-16805-7-git-send-email-leo.yan@linaro.org > > > Signed-off-by: Arnaldo Carvalho de Melo <acme@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
Em Thu, Dec 13, 2018 at 10:21:26AM -0300, Arnaldo Carvalho de Melo escreveu: > Em Thu, Dec 13, 2018 at 09:09:49PM +0800, leo.yan@linaro.org escreveu: > > Thanks a lot for helping. If you prefer me to resend the patch set, > > also let me know. > > I can fix it, here. Can I take a look at the result: https://git.kernel.org/acme/c/222b0bead7e4 ? - Arnaldo
On Thu, Dec 13, 2018 at 10:26:33AM -0300, Arnaldo Carvalho de Melo wrote: > Em Thu, Dec 13, 2018 at 10:21:26AM -0300, Arnaldo Carvalho de Melo escreveu: > > Em Thu, Dec 13, 2018 at 09:09:49PM +0800, leo.yan@linaro.org escreveu: > > > Thanks a lot for helping. If you prefer me to resend the patch set, > > > also let me know. > > > > I can fix it, here. > > Can I take a look at the result: > > https://git.kernel.org/acme/c/222b0bead7e4 Yeah, looks good to me :) Thanks, Leo Yan
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 1039f364..bee026e 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);