diff options
Diffstat (limited to 'tools/perf/Documentation/perf-intel-pt.txt')
| -rw-r--r-- | tools/perf/Documentation/perf-intel-pt.txt | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-intel-pt.txt b/tools/perf/Documentation/perf-intel-pt.txt index f9fe4a4040ba..d5a266d7f15b 100644 --- a/tools/perf/Documentation/perf-intel-pt.txt +++ b/tools/perf/Documentation/perf-intel-pt.txt @@ -999,6 +999,21 @@ What *will* be decoded with the (single) q option: Note the q option does not specify what events will be synthesized e.g. the p option must be used also to show power events. +Repeating the q option (double-q i.e. qq) results in even faster decoding and even +less detail. The decoder decodes only extended PSB (PSB+) packets, getting the +instruction pointer if there is a FUP packet within PSB+ (i.e. between PSB and +PSBEND). Note PSB packets occur regularly in the trace based on the psb_period +config term (refer config terms section). There will be a FUP packet if the +PSB+ occurs while control flow is being traced. + +What will *not* be decoded with the qq option: + + - everything except instruction pointer associated with PSB packets + +What *will* be decoded with the qq option: + + - instruction pointer associated with PSB packets + dump option ~~~~~~~~~~~ |