Re: [PATCH 6/7] perf record: Add switch-output size option argument

[Arnaldo Carvalho de Melo]

Em Tue, Jan 03, 2017 at 11:20:27AM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Tue, Jan 03, 2017 at 09:19:59AM +0100, Jiri Olsa escreveu:
> > 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.

BTW, the first three patches are trivial and were merged, thanks,

- Arnaldo
 
>   s/does/goes/g
> 
> But:
> 
> [root@jouet ~]# perf record -F9000 -a --switch-output=1K sleep 5
> [ perf record: dump data: Woken up 0 times ]
> [ perf record: Dump perf.data.2017010311185502 ]
> [ perf record: dump data: Woken up 1 times ]
> [ perf record: Dump perf.data.2017010311190003 ]
> [ perf record: Woken up 0 times to write data ]
> [ perf record: Dump perf.data.2017010311190020 ]
> [ perf record: Captured and wrote 2.240 MB perf.data.<timestamp> ]
> [root@jouet ~]# ls -larth perf.data.*
> -rw-------. 1 root root 2.3M Jan  3 11:18 perf.data.2017010311181984
> -rw-------. 1 root root 2.3M Jan  3 11:18 perf.data.2017010311182002
> -rw-------. 1 root root 2.3M Jan  3 11:18 perf.data.2017010311185502
> -rw-------. 1 root root 2.3M Jan  3 11:19 perf.data.2017010311190003
> -rw-------. 1 root root 2.3M Jan  3 11:19 perf.data.2017010311190020
> [root@jouet ~]#
> 
> What is that I am missing?
> 
> - Arnaldo
>  
> >   $ 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 <jolsa@xxxxxxxxxx>
> > Cc: David Ahern <dsahern@xxxxxxxxx>
> > Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
> > Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> > Cc: Wang Nan <wangnan0@xxxxxxxxxx>
> > Link: http://lkml.kernel.org/n/tip-xw4x8qj6aojox378q9ley29e@xxxxxxxxxxxxxx
> > ---
> >  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