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Diffstat (limited to 'tools/perf/Documentation/perf-record.txt')
| -rw-r--r-- | tools/perf/Documentation/perf-record.txt | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index 9ccc75935bc5..465be4e62a17 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -713,6 +713,40 @@ measurements: wait -n ${perf_pid} exit $? +--threads=<spec>:: +Write collected trace data into several data files using parallel threads. +<spec> value can be user defined list of masks. Masks separated by colon +define CPUs to be monitored by a thread and affinity mask of that thread +is separated by slash: + + <cpus mask 1>/<affinity mask 1>:<cpus mask 2>/<affinity mask 2>:... + +CPUs or affinity masks must not overlap with other corresponding masks. +Invalid CPUs are ignored, but masks containing only invalid CPUs are not +allowed. + +For example user specification like the following: + + 0,2-4/2-4:1,5-7/5-7 + +specifies parallel threads layout that consists of two threads, +the first thread monitors CPUs 0 and 2-4 with the affinity mask 2-4, +the second monitors CPUs 1 and 5-7 with the affinity mask 5-7. + +<spec> value can also be a string meaning predefined parallel threads +layout: + + cpu - create new data streaming thread for every monitored cpu + core - create new thread to monitor CPUs grouped by a core + package - create new thread to monitor CPUs grouped by a package + numa - create new threed to monitor CPUs grouped by a NUMA domain + +Predefined layouts can be used on systems with large number of CPUs in +order not to spawn multiple per-cpu streaming threads but still avoid LOST +events in data directory files. Option specified with no or empty value +defaults to CPU layout. Masks defined or provided by the option value are +filtered through the mask provided by -C option. + include::intel-hybrid.txt[] --debuginfod[=URLs]:: |