diff options
Diffstat (limited to 'tools/perf/Documentation/perf-record.txt')
| -rw-r--r-- | tools/perf/Documentation/perf-record.txt | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index 92335193dc33..5054d9147f0f 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -45,9 +45,9 @@ OPTIONS param1 and param2 are defined as formats for the PMU in: /sys/bus/event_source/devices/<pmu>/format/* - There are also some params which are not defined in .../<pmu>/format/*. + There are also some parameters which are not defined in .../<pmu>/format/*. These params can be used to overload default config values per event. - Here is a list of the params. + Here are some common parameters: - 'period': Set event sampling period - 'freq': Set event sampling frequency - 'time': Disable/enable time stamping. Acceptable values are 1 for @@ -57,8 +57,11 @@ OPTIONS FP mode, "dwarf" for DWARF mode, "lbr" for LBR mode and "no" for disable callgraph. - 'stack-size': user stack size for dwarf mode + + See the linkperf:perf-list[1] man page for more parameters. + Note: If user explicitly sets options which conflict with the params, - the value set by the params will be overridden. + the value set by the parameters will be overridden. Also not defined in .../<pmu>/format/* are PMU driver specific configuration parameters. Any configuration parameter preceded by @@ -427,6 +430,10 @@ that gets then processed, possibly via a perf script, to decide if that particular perf.data snapshot should be kept or not. Implies --timestamp-filename, --no-buildid and --no-buildid-cache. +The reason for the latter two is to reduce the data file switching +overhead. You can still switch them on with: + + --switch-output --no-no-buildid --no-no-buildid-cache --dry-run:: Parse options then exit. --dry-run can be used to detect errors in cmdline |
