It's now possible to specify the threshold size for perf.data like: $ perf record --switch-output=2G ...
Once it's reached, the current data are dumped in to the perf.data.<timestamp> file and session does on. $ perf record --switch-output=2G ... [ perf record: dump data: Woken up 7244 times ] [ perf record: Dump perf.data.2017010214093746 ] ... The size is expected to be a number with appended unit character - B/K/M/G. Signed-off-by: Jiri Olsa <jo...@kernel.org> Cc: David Ahern <dsah...@gmail.com> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Peter Zijlstra <a.p.zijls...@chello.nl> Cc: Wang Nan <wangn...@huawei.com> Link: http://lkml.kernel.org/n/tip-xw4x8qj6aojox378q9ley...@git.kernel.org --- tools/perf/Documentation/perf-record.txt | 7 +++- tools/perf/builtin-record.c | 66 ++++++++++++++++++++++++++------ 2 files changed, 59 insertions(+), 14 deletions(-) diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index 5054d9147f0f..d838354df417 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -421,9 +421,12 @@ Configure all used events to run in user space. --timestamp-filename Append timestamp to output file name. ---switch-output:: +--switch-output[=mode]:: Generate multiple perf.data files, timestamp prefixed, switching to a new one -when receiving a SIGUSR2. +based on 'mode' value: + "signal" - when receiving a SIGUSR2 (default value) or + <size> - when reaching the size threshold, size is expected to + be a number with appended unit character - B/K/M/G 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 diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index b503e5ebc1e7..42321a0fa80e 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -47,7 +47,9 @@ #include <linux/time64.h> struct switch_output { + bool enabled; bool signal; + unsigned long size; const char *str; bool set; }; @@ -72,6 +74,23 @@ struct record { unsigned long long samples; }; +static volatile int auxtrace_record__snapshot_started; +static DEFINE_TRIGGER(auxtrace_snapshot_trigger); +static DEFINE_TRIGGER(switch_output_trigger); + +static bool switch_output_signal(struct record *rec) +{ + return rec->switch_output.signal && + trigger_is_ready(&switch_output_trigger); +} + +static bool switch_output_size(struct record *rec) +{ + return rec->switch_output.size && + trigger_is_ready(&switch_output_trigger) && + (rec->bytes_written >= rec->switch_output.size); +} + static int record__write(struct record *rec, void *bf, size_t size) { if (perf_data_file__write(rec->session->file, bf, size) < 0) { @@ -80,6 +99,10 @@ static int record__write(struct record *rec, void *bf, size_t size) } rec->bytes_written += size; + + if (switch_output_size(rec)) + trigger_hit(&switch_output_trigger); + return 0; } @@ -199,10 +222,6 @@ static volatile int done; static volatile int signr = -1; static volatile int child_finished; -static volatile int auxtrace_record__snapshot_started; -static DEFINE_TRIGGER(auxtrace_snapshot_trigger); -static DEFINE_TRIGGER(switch_output_trigger); - static void sig_handler(int sig) { if (sig == SIGCHLD) @@ -848,11 +867,11 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) signal(SIGTERM, sig_handler); signal(SIGSEGV, sigsegv_handler); - if (rec->opts.auxtrace_snapshot_mode || rec->switch_output.signal) { + if (rec->opts.auxtrace_snapshot_mode || rec->switch_output.enabled) { signal(SIGUSR2, snapshot_sig_handler); if (rec->opts.auxtrace_snapshot_mode) trigger_on(&auxtrace_snapshot_trigger); - if (rec->switch_output.signal) + if (rec->switch_output.enabled) trigger_on(&switch_output_trigger); } else { signal(SIGUSR2, SIG_IGN); @@ -1360,13 +1379,33 @@ static int record__parse_mmap_pages(const struct option *opt, static int switch_output_setup(struct switch_output *s) { + unsigned long val; + static struct parse_tag tags_size[] = { + { .tag = 'B', .mult = 1 }, + { .tag = 'K', .mult = 1 << 10 }, + { .tag = 'M', .mult = 1 << 20 }, + { .tag = 'G', .mult = 1 << 30 }, + { .tag = 0 }, + }; + if (!strcmp(s->str, "signal")) { s->signal = true; pr_debug("switch-output with SIGUSR2 signal\n"); - return 0; + goto enabled; + } + + val = parse_tag_value(s->str, tags_size); + if (val != (unsigned long) -1) { + s->size = val; + pr_debug("switch-output with %s size threshold\n", s->str); + goto enabled; } return -1; + +enabled: + s->enabled = true; + return 0; } static const char * const __record_usage[] = { @@ -1537,8 +1576,9 @@ static struct option __record_options[] = { OPT_BOOLEAN(0, "timestamp-filename", &record.timestamp_filename, "append timestamp to output filename"), OPT_STRING_OPTARG_SET(0, "switch-output", &record.switch_output.str, - &record.switch_output.set, "signal", - "Switch output when receive SIGUSR2", "signal"), + &record.switch_output.set, "signal,size", + "Switch output when receive SIGUSR2 or cross size threshold", + "signal"), OPT_BOOLEAN(0, "dry-run", &dry_run, "Parse options then exit"), OPT_END() @@ -1602,7 +1642,7 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused) return -EINVAL; } - if (rec->switch_output.signal) + if (rec->switch_output.enabled) rec->timestamp_filename = true; if (!rec->itr) { @@ -1653,7 +1693,7 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused) if (rec->no_buildid_cache || rec->no_buildid) { disable_buildid_cache(); - } else if (rec->switch_output.signal) { + } else if (rec->switch_output.enabled) { /* * In 'perf record --switch-output', disable buildid * generation by default to reduce data file switching @@ -1745,6 +1785,8 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused) static void snapshot_sig_handler(int sig __maybe_unused) { + struct record *rec = &record; + if (trigger_is_ready(&auxtrace_snapshot_trigger)) { trigger_hit(&auxtrace_snapshot_trigger); auxtrace_record__snapshot_started = 1; @@ -1752,6 +1794,6 @@ static void snapshot_sig_handler(int sig __maybe_unused) trigger_error(&auxtrace_snapshot_trigger); } - if (trigger_is_ready(&switch_output_trigger)) + if (switch_output_signal(rec)) trigger_hit(&switch_output_trigger); } -- 2.7.4
