perf tools: Fix Intel BTS/PT timestamp handling
Adrian Hunter
reviewerPATCH 1/1 perf tools: Fix Intel BTS/PT timestamp handling
Events that don't sample the timestamp have a timestamp value of -1. Intel BTS and Intel PT processing wasn't taking that into account. This is particularly noticeable with Intel BTS because timestamps are not requested by default. Then, if the conversion of -1 to TSC results in a small number, the processing is unaffected. However if the conversion results in a big number, then the data is processed prematurely before relevant sideband data like mmap events, which in turn results in samples with unknown dsos.
--- tools/perf/util/intel-bts.c | 2 +- tools/perf/util/intel-pt.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
tools/perf/util/intel-bts.c +1 -1
@@ -610,7 +610,7 @@ static int intel_bts_process_event(struct perf_session *session,return -EINVAL ; } -if (sample->time) +if (sample->time && sample->time != (u64)-1 ) timestamp =perf_time_to_tsc (sample->time, &bts->tc);else timestamp =0 ;
tools/perf/util/intel-pt.c +1 -1
@@ -1450,7 +1450,7 @@ static int intel_pt_process_event(struct perf_session *session,return -EINVAL ; } -if (sample->time) +if (sample->time && sample->time != (u64)-1 ) timestamp =perf_time_to_tsc (sample->time, &pt->tc);else timestamp =0 ;
Signature · 1 line
1.9.1
Arnaldo Carvalho de Melo
maintainerEm Thu, Aug 20, 2015 at 11:51:32AM +0300, Adrian Hunter escreveu:
Quoted 10 lines
Events that don't sample the timestamp have a timestamp value of -1. Intel BTS and Intel PT processing wasn't taking that into account. This is particularly noticeable with Intel BTS because timestamps are not requested by default. Then, if the conversion of -1 to TSC results in a small number, the processing is unaffected. However if the conversion results in a big number, then the data is processed prematurely before relevant sideband data like mmap events, which in turn results in samples with unknown dsos.
Thanks, since the BTS code is not in, I'm splitting it from here, so that this one only fixes what is upstream already, i.e. PT, and will fold the BTS part with the patch introducing BTS,
- Arnaldo
Quoted 34 lines
Signed-off-by Adrian Hunter <[email protected]>--- tools/perf/util/intel-bts.c | 2 +- tools/perf/util/intel-pt.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)tools/perf/util/intel-bts.c +1
-1@@ -610,7 +610,7 @@ static int intel_bts_process_event(struct perf_session *session,return -EINVAL ; } -if (sample->time) +if (sample->time && sample->time != (u64)-1 ) timestamp =perf_time_to_tsc (sample->time, &bts->tc);else timestamp =0 ;tools/perf/util/intel-pt.c +1
-1@@ -1450,7 +1450,7 @@ static int intel_pt_process_event(struct perf_session *session,return -EINVAL ; } -if (sample->time) +if (sample->time && sample->time != (u64)-1 ) timestamp =perf_time_to_tsc (sample->time, &pt->tc);else timestamp =0 ;Signature · 1 line
1.9.1
tip-bot for Adrian Hunter
merge bot[tip:perf/core] perf tools: Fix Intel PT timestamp handling
In reply to Adrian Hunterperf tools: Fix Intel PT timestamp handling
Commit-ID: 81cd60cc29a9c3e92ad6ca167a4764b2c2d2fc04 Gitweb: http://git.kernel.org/tip/81cd60cc29a9c3e92ad6ca167a4764b2c2d2fc04 Author: Adrian Hunter <[email protected]> AuthorDate: Thu, 20 Aug 2015 11:51:32 +0300 Committer: Arnaldo Carvalho de Melo <[email protected]> CommitDate: Fri, 21 Aug 2015 10:29:23 -0300
perf tools: Fix Intel PT timestamp handling
Events that don't sample the timestamp have a timestamp value of -1.
Intel PT processing wasn't taking that into account.
This is particularly noticeable with Intel BTS because timestamps are not requested by default.
Then, if the conversion of -1 to TSC results in a small number, the processing is unaffected.
However if the conversion results in a big number, then the data is processed prematurely before relevant sideband data like mmap events, which in turn results in samples with unknown dsos.
Commiter note:
Since BTS wasn't upstream, I split the patch to fold the BTS part with the patch introducing it, to avoid having this bug in the commit history. PT was already upstream, so this patch contains that part.
--- tools/perf/util/intel-pt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
tools/perf/util/intel-pt.c +1 -1
@@ -1450,7 +1450,7 @@ static int intel_pt_process_event(struct perf_session *session,return -EINVAL ; } -if (sample->time) +if (sample->time && sample->time != (u64)-1 ) timestamp =perf_time_to_tsc (sample->time, &pt->tc);else timestamp =0 ;