perf intel-pt: Fix occasional decoding errors when tracing system-wide
Adrian Hunter
reviewerPATCH 1/1 perf intel-pt: Fix occasional decoding errors when tracing system-wide
In order to successfully decode Intel PT traces, context switch events are needed from the moment the trace starts. Currently that is ensured by using the 'immediate' flag which enables the switch event when it is opened. However, since commit 86c2786994bd ("perf intel-pt: Add support for PERF_RECORD_SWITCH") that might not always happen. When tracing system-wide the context switch event is added to the tracking event which was not set as 'immediate'. Change that so it is.
--- tools/perf/arch/x86/util/intel-pt.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
tools/perf/arch/x86/util/intel-pt.c +5 -1
@@ -501,7 +501,7 @@ static int intel_pt_recording_options(struct auxtrace_record *itr,struct intel_pt_recording *ptr = container_of(itr, struct intel_pt_recording, itr);struct perf_pmu *intel_pt_pmu = ptr->intel_pt_pmu; -bool have_timing_info; +bool have_timing_info, need_immediate = false;struct perf_evsel *evsel, *intel_pt_evsel =NULL ;const struct cpu_map *cpus = evlist->cpus;bool privileged =geteuid () ==0 ||perf_event_paranoid () <0 ;
@@ -655,6 +655,7 @@ static int intel_pt_recording_options(struct auxtrace_record *itr, ptr->have_sched_switch =3 ; }else { opts->record_switch_events = true; + need_immediate = true;if (cpu_wide) ptr->have_sched_switch =3 ;else
@@ -700,6 +701,9 @@ static int intel_pt_recording_options(struct auxtrace_record *itr, tracking_evsel->attr.freq =0 ; tracking_evsel->attr.sample_period =1 ; +if (need_immediate) + tracking_evsel->immediate = true; +/* In per-cpu case, always need the time of mmap events etc */ if (!cpu_map__empty (cpus)) {perf_evsel__set_sample_bit (tracking_evsel,TIME );
Signature · 1 line
1.9.1
tip-bot for Adrian Hunter
merge botperf intel-pt: Fix occasional decoding errors when tracing system-wide
Commit-ID: 3d918fb13abdbeca7947578f5d7e426eafad7f5e Gitweb: http://git.kernel.org/tip/3d918fb13abdbeca7947578f5d7e426eafad7f5e Author: Adrian Hunter <[email protected]> AuthorDate: Mon, 15 Aug 2016 10:23:04 +0300 Committer: Arnaldo Carvalho de Melo <[email protected]> CommitDate: Mon, 15 Aug 2016 18:11:18 -0300
perf intel-pt: Fix occasional decoding errors when tracing system-wide
In order to successfully decode Intel PT traces, context switch events are needed from the moment the trace starts. Currently that is ensured by using the 'immediate' flag which enables the switch event when it is opened.
However, since commit 86c2786994bd ("perf intel-pt: Add support for PERF_RECORD_SWITCH") that might not always happen. When tracing system-wide the context switch event is added to the tracking event which was not set as 'immediate'. Change that so it is.
--- tools/perf/arch/x86/util/intel-pt.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
tools/perf/arch/x86/util/intel-pt.c +5 -1
@@ -501,7 +501,7 @@ static int intel_pt_recording_options(struct auxtrace_record *itr,struct intel_pt_recording *ptr = container_of(itr, struct intel_pt_recording, itr);struct perf_pmu *intel_pt_pmu = ptr->intel_pt_pmu; -bool have_timing_info; +bool have_timing_info, need_immediate = false;struct perf_evsel *evsel, *intel_pt_evsel =NULL ;const struct cpu_map *cpus = evlist->cpus;bool privileged =geteuid () ==0 ||perf_event_paranoid () <0 ;
@@ -655,6 +655,7 @@ static int intel_pt_recording_options(struct auxtrace_record *itr, ptr->have_sched_switch =3 ; }else { opts->record_switch_events = true; + need_immediate = true;if (cpu_wide) ptr->have_sched_switch =3 ;else
@@ -700,6 +701,9 @@ static int intel_pt_recording_options(struct auxtrace_record *itr, tracking_evsel->attr.freq =0 ; tracking_evsel->attr.sample_period =1 ; +if (need_immediate) + tracking_evsel->immediate = true; +/* In per-cpu case, always need the time of mmap events etc */ if (!cpu_map__empty (cpus)) {perf_evsel__set_sample_bit (tracking_evsel,TIME );