Em Thu, Apr 14, 2016 at 02:22:01PM +0000, Wang Nan escreveu: > Allow 'perf record' splits its output into multiple files. > > For example: > > # ~/perf record -a --timestamp-filename --switch-output & > [1] 10763 > # kill -s SIGUSR2 10763 > [ perf record: dump data: Woken up 1 times ] > # [ perf record: Dump perf.data.2015122622314468 ] > > # kill -s SIGUSR2 10763 > [ perf record: dump data: Woken up 1 times ] > # [ perf record: Dump perf.data.2015122622314762 ] > > # kill -s SIGUSR2 10763 > [ perf record: dump data: Woken up 1 times ] > #[ perf record: Dump perf.data.2015122622315171 ] > > # fg > perf record -a --timestamp-filename --switch-output > ^C[ perf record: Woken up 1 times to write data ] > [ perf record: Dump perf.data.2015122622315513 ] > [ perf record: Captured and wrote 0.014 MB perf.data.<timestamp> (296 > samples) ]
Added this as an initial man page entry: diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index 19aa17532a16..a77a431ca4ef 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -347,6 +347,14 @@ Configure all used events to run in kernel space. --all-user:: Configure all used events to run in user space. +--switch-output:: +Generate multiple perf.data files, timestamp prefixed, switching to a new one +when receiving a SIGUSR2. + +A possible use case is to, given an external event, slice the perf.data file +that gets then processed, possibly via a perf script, to decide if that +particular perf.data snapshot should be kept or not. + SEE ALSO -------- linkperf:perf-stat[1], linkperf:perf-list[1]
