| From 1b6599a9d8e6c9f7e9b0476012383b1777f7fc93 Mon Sep 17 00:00:00 2001 |
| From: Adrian Hunter <adrian.hunter@intel.com> |
| Date: Fri, 10 May 2019 15:41:43 +0300 |
| Subject: perf intel-pt: Fix sample timestamp wrt non-taken branches |
| |
| From: Adrian Hunter <adrian.hunter@intel.com> |
| |
| commit 1b6599a9d8e6c9f7e9b0476012383b1777f7fc93 upstream. |
| |
| The sample timestamp is updated to ensure that the timestamp represents |
| the time of the sample and not a branch that the decoder is still |
| walking towards. The sample timestamp is updated when the decoder |
| returns, but the decoder does not return for non-taken branches. Update |
| the sample timestamp then also. |
| |
| Note that commit 3f04d98e972b5 ("perf intel-pt: Improve sample |
| timestamp") was also a stable fix and appears, for example, in v4.4 |
| stable tree as commit a4ebb58fd124 ("perf intel-pt: Improve sample |
| timestamp"). |
| |
| Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> |
| Cc: Jiri Olsa <jolsa@redhat.com> |
| Cc: stable@vger.kernel.org # v4.4+ |
| Fixes: 3f04d98e972b ("perf intel-pt: Improve sample timestamp") |
| Link: http://lkml.kernel.org/r/20190510124143.27054-4-adrian.hunter@intel.com |
| Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 5 ++++- |
| 1 file changed, 4 insertions(+), 1 deletion(-) |
| |
| --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c |
| +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c |
| @@ -1235,8 +1235,11 @@ static int intel_pt_walk_tnt(struct inte |
| return 0; |
| } |
| decoder->ip += intel_pt_insn.length; |
| - if (!decoder->tnt.count) |
| + if (!decoder->tnt.count) { |
| + decoder->sample_timestamp = decoder->timestamp; |
| + decoder->sample_insn_cnt = decoder->timestamp_insn_cnt; |
| return -EAGAIN; |
| + } |
| decoder->tnt.payload <<= 1; |
| continue; |
| } |
