Allow 'perf record' to split 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) ] # ls -l total 920 -rw------- 1 root root 797692 Dec 26 22:31 perf.data.2015122622314468 -rw------- 1 root root 59960 Dec 26 22:31 perf.data.2015122622314762 -rw------- 1 root root 59912 Dec 26 22:31 perf.data.2015122622315171 -rw------- 1 root root 19220 Dec 26 22:31 perf.data.2015122622315513 Signed-off-by: Wang Nan <wangn...@huawei.com> Tested-by: Arnaldo Carvalho de Melo <a...@redhat.com> Cc: Adrian Hunter <adrian.hun...@intel.com> Cc: Jiri Olsa <jo...@kernel.org> Cc: Masami Hiramatsu <mhira...@kernel.org> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Zefan Li <lize...@huawei.com> Cc: pi3or...@163.com Link: http://lkml.kernel.org/r/1460643725-167413-3-git-send-email-wangn...@huawei.com Signed-off-by: He Kuang <heku...@huawei.com> [ Added man page entry ] Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/Documentation/perf-record.txt | 8 ++++++ tools/perf/builtin-record.c | 44 +++++++++++++++++++++++++++----- 2 files changed, 45 insertions(+), 7 deletions(-) diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index 19aa175..a77a431 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] diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 0ff2422..7fd0b2d 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -58,6 +58,7 @@ struct record { bool no_buildid_cache_set; bool buildid_all; bool timestamp_filename; + bool switch_output; unsigned long long samples; }; @@ -130,6 +131,8 @@ static volatile int child_finished; static DEFINE_TRIGGER(auxtrace_snapshot); +static DEFINE_TRIGGER(switch_output); + static void sig_handler(int sig) { if (sig == SIGCHLD) @@ -649,9 +652,12 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) signal(SIGINT, sig_handler); signal(SIGTERM, sig_handler); - if (rec->opts.auxtrace_snapshot_mode) { + if (rec->opts.auxtrace_snapshot_mode || rec->switch_output) { signal(SIGUSR2, snapshot_sig_handler); - auxtrace_snapshot_on(); + if (rec->opts.auxtrace_snapshot_mode) + auxtrace_snapshot_on(); + if (rec->switch_output) + switch_output_on(); } else { signal(SIGUSR2, SIG_IGN); } @@ -781,11 +787,13 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) } auxtrace_snapshot_ready(); + switch_output_ready(); for (;;) { unsigned long long hits = rec->samples; if (record__mmap_read_all(rec) < 0) { auxtrace_snapshot_error(); + switch_output_error(); err = -1; goto out_child; } @@ -801,6 +809,22 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) } } + if (switch_output_is_toggled()) { + switch_output_ready(); + + if (!quiet) + fprintf(stderr, "[ perf record: dump data: Woken up %ld times ]\n", + waking); + waking = 0; + fd = record__switch_output(rec, false); + if (fd < 0) { + pr_err("Failed to switch to new file\n"); + switch_output_error(); + err = fd; + goto out_child; + } + } + if (hits == rec->samples) { if (done || draining) break; @@ -829,6 +853,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) } } auxtrace_snapshot_off(); + switch_output_off(); if (forks && workload_exec_errno) { char msg[STRERR_BUFSIZE]; @@ -1264,6 +1289,8 @@ struct option __record_options[] = { "Record build-id of all DSOs regardless of hits"), OPT_BOOLEAN(0, "timestamp-filename", &record.timestamp_filename, "append timestamp to output filename"), + OPT_BOOLEAN(0, "switch-output", &record.switch_output, + "Switch output when receive SIGUSR2"), OPT_END() }; @@ -1412,9 +1439,12 @@ out_symbol_exit: static void snapshot_sig_handler(int sig __maybe_unused) { - if (!auxtrace_snapshot_is_ready()) - return; - auxtrace_snapshot_toggle(); - if (auxtrace_record__snapshot_start(record.itr)) - auxtrace_snapshot_error(); + if (auxtrace_snapshot_is_ready()) { + auxtrace_snapshot_toggle(); + if (auxtrace_record__snapshot_start(record.itr)) + auxtrace_snapshot_error(); + } + + if (switch_output_is_ready()) + switch_output_toggle(); } -- 1.8.3.4
