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perf record: Add switch-output size option argument 

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 <jolsa@kernel.org>
Acked-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1483955520-29063-5-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
hifive-unleashed-5.1
Jiri Olsa 2017-01-09 10:51:58 +01:00 committed by Arnaldo Carvalho de Melo
parent cb4e1ebb6a
commit dc0c6127c2
2 changed files with 63 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
tools/perf/Documentation/perf-record.txt
View File

@ -421,9 +421,17 @@ 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
Note: the precision of the size threshold hugely depends
on your configuration - the number and size of your ring
buffers (-m). It is generally more precise for higher sizes
(like >5M), for lower values expect different sizes.
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

67
tools/perf/builtin-record.c
View File

@ -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);
@ -1361,6 +1380,14 @@ out_free:
static int switch_output_setup(struct record *rec)
{
struct switch_output *s = &rec->switch_output;
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 },
};
unsigned long val;
if (!s->set)
return 0;
@ -1368,10 +1395,22 @@ static int switch_output_setup(struct record *rec)
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:
rec->timestamp_filename = true;
s->enabled = true;
return 0;
}
static const char * const __record_usage[] = {
@ -1542,8 +1581,9 @@ 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()
@ -1606,9 +1646,6 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
return -EINVAL;
}
if (rec->switch_output.signal)
rec->timestamp_filename = true;
if (!rec->itr) {
rec->itr = auxtrace_record__init(rec->evlist, &err);
if (err)
@ -1657,7 +1694,7 @@ 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
@ -1749,6 +1786,8 @@ out:
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;
@ -1756,6 +1795,6 @@ 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);
}