diff options
| author | Adrian Hunter <adrian.hunter@intel.com> | 2022-09-05 10:34:23 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2022-10-04 08:55:21 -0300 |
| commit | 65aee81afe7f6a54e2fb2de59e1d6cd47dcf8eb9 (patch) | |
| tree | fe33e48c6b705df189d3cc73ae2216d7fb98cceb /tools/perf/Documentation | |
| parent | 50d7620b27d19bfa4cc12764d27c272f2ee3e28a (diff) | |
perf intel-pt: Support itrace option flag d+e to log on error
Pass d+e option and log size via intel_pt_log_enable(). Allocate a buffer
for log messages and provide intel_pt_log_dump_buf() to dump and reset the
buffer upon decoder errors.
Example:
$ sudo perf record -e intel_pt// sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.094 MB perf.data ]
$ sudo perf config itrace.debug-log-buffer-size=300
$ sudo perf script --itrace=ed+e+o | head -20
Dumping debug log buffer (first line may be sliced)
Other
ffffffff96ca22f6: 48 89 e5 Other
ffffffff96ca22f9: 65 48 8b 05 ff e0 38 69 Other
ffffffff96ca2301: 48 3d c0 a5 c1 98 Other
ffffffff96ca2307: 74 08 Jcc +8
ffffffff96ca2311: 5d Other
ffffffff96ca2312: c3 Ret
ERROR: Bad RET compression (TNT=N) at 0xffffffff96ca2312
End of debug log buffer dump
instruction trace error type 1 time 15913.537143482 cpu 5 pid 36292 tid 36292 ip 0xffffffff96ca2312 code 6: Trace doesn't match instruction
Dumping debug log buffer (first line may be sliced)
Other
ffffffff96ce7fe9: f6 47 2e 20 Other
ffffffff96ce7fed: 74 11 Jcc +17
ffffffff96ce7fef: 48 8b 87 28 0a 00 00 Other
ffffffff96ce7ff6: 5d Other
ffffffff96ce7ff7: 48 8b 40 18 Other
ffffffff96ce7ffb: c3 Ret
ERROR: Bad RET compression (TNT=N) at 0xffffffff96ce7ffb
Warning:
8 instruction trace errors
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220905073424.3971-6-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/Documentation')
| -rw-r--r-- | tools/perf/Documentation/perf-intel-pt.txt | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/tools/perf/Documentation/perf-intel-pt.txt b/tools/perf/Documentation/perf-intel-pt.txt index d5ddb968bcf4..92464a5d7eaf 100644 --- a/tools/perf/Documentation/perf-intel-pt.txt +++ b/tools/perf/Documentation/perf-intel-pt.txt @@ -989,10 +989,13 @@ must be preceded by either '+' or '-'. The flags support by Intel PT are: -a Suppress logging of perf events +a Log all perf events + +e Output only on decoding errors (size configurable) +o Output to stdout instead of "intel_pt.log" By default, logged perf events are filtered by any specified time ranges, but -flag +a overrides that. +flag +a overrides that. The +e flag can be useful for analyzing errors. By +default, the log size in that case is 16384 bytes, but can be altered by +linkperf:perf-config[1] e.g. perf config itrace.debug-log-buffer-size=30000 In addition, the period of the "instructions" event can be specified. e.g. |