diff options
Diffstat (limited to 'tools/perf/Documentation/perf-stat.txt')
| -rw-r--r-- | tools/perf/Documentation/perf-stat.txt | 35 |
1 files changed, 34 insertions, 1 deletions
diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt index 4d56586b2fb9..b029ee728a0b 100644 --- a/tools/perf/Documentation/perf-stat.txt +++ b/tools/perf/Documentation/perf-stat.txt @@ -71,6 +71,16 @@ report:: --tid=<tid>:: stat events on existing thread id (comma separated list) +ifdef::HAVE_LIBPFM[] +--pfm-events events:: +Select a PMU event using libpfm4 syntax (see http://perfmon2.sf.net) +including support for event filters. For example '--pfm-events +inst_retired:any_p:u:c=1:i'. More than one event can be passed to the +option using the comma separator. Hardware events and generic hardware +events cannot be mixed together. The latter must be used with the -e +option. The -e option and this one can be mixed and matched. Events +can be grouped using the {} notation. +endif::HAVE_LIBPFM[] -a:: --all-cpus:: @@ -93,7 +103,9 @@ report:: -B:: --big-num:: - print large numbers with thousands' separators according to locale + print large numbers with thousands' separators according to locale. + Enabled by default. Use "--no-big-num" to disable. + Default setting can be changed with "perf config stat.big-num=false". -C:: --cpu=:: @@ -176,6 +188,8 @@ Print count deltas every N milliseconds (minimum: 1ms) The overhead percentage could be high in some cases, for instance with small, sub 100ms intervals. Use with caution. example: 'perf stat -I 1000 -e cycles -a sleep 5' +If the metric exists, it is calculated by the counts generated in this interval and the metric is printed after #. + --interval-count times:: Print count deltas for fixed number of times. This option should be used together with "-I" option. @@ -232,6 +246,25 @@ filter out the startup phase of the program, which is often very different. Print statistics of transactional execution if supported. +--metric-no-group:: +By default, events to compute a metric are placed in weak groups. The +group tries to enforce scheduling all or none of the events. The +--metric-no-group option places events outside of groups and may +increase the chance of the event being scheduled - leading to more +accuracy. However, as events may not be scheduled together accuracy +for metrics like instructions per cycle can be lower - as both metrics +may no longer be being measured at the same time. + +--metric-no-merge:: +By default metric events in different weak groups can be shared if one +group contains all the events needed by another. In such cases one +group will be eliminated reducing event multiplexing and making it so +that certain groups of metrics sum to 100%. A downside to sharing a +group is that the group may require multiplexing and so accuracy for a +small group that need not have multiplexing is lowered. This option +forbids the event merging logic from sharing events between groups and +may be used to increase accuracy in this case. + STAT RECORD ----------- Stores stat data into perf data file. |