The meaning of perf record's "overwrite" option and many "overwrite" in
source code are not clear. In perf's code, the 'overwrite' has 2 meanings:
1. Make ringbuffer readonly (perf_evlist__mmap_ex's argument).
2. Set evsel's "backward" attribute (in apply_config_terms).
perf record doesn't use meaning 1 at all, but have a overwrite option, its
real meaning is setting backward.
This patch separates these two concepts, introduce 'flightrecorder' mode
which is what we really want. It combines these 2 concept together, wraps
them into a record mode. In flight recorder mode, perf only dumps data before
something happen.
Signed-off-by: Wang Nan <wangn...@huawei.com>
---
tools/perf/Documentation/perf-record.txt | 8 ++++----
tools/perf/builtin-record.c | 4 ++--
tools/perf/perf.h | 2 +-
tools/perf/util/evsel.c | 6 +++---
tools/perf/util/evsel.h | 4 ++--
tools/perf/util/parse-events.c | 20 ++++++++++----------
tools/perf/util/parse-events.h | 4 ++--
tools/perf/util/parse-events.l | 4 ++--
8 files changed, 26 insertions(+), 26 deletions(-)
diff --git a/tools/perf/Documentation/perf-record.txt
b/tools/perf/Documentation/perf-record.txt
index 5a626ef..463c2d3 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -467,19 +467,19 @@ the beginning of record, collect them during finalizing
an output file.
The collected non-sample events reflects the status of the system when
record is finished.
---overwrite::
+--flight-recorder::
Makes all events use an overwritable ring buffer. An overwritable ring
buffer works like a flight recorder: when it gets full, the kernel will
overwrite the oldest records, that thus will never make it to the
perf.data file.
-When '--overwrite' and '--switch-output' are used perf records and drops
+When '--flight-recorder' and '--switch-output' are used perf records and drops
events until it receives a signal, meaning that something unusual was
detected that warrants taking a snapshot of the most current events,
those fitting in the ring buffer at that moment.
-'overwrite' attribute can also be set or canceled for an event using
-config terms. For example: 'cycles/overwrite/' and
'instructions/no-overwrite/'.
+'flightrecorder' attribute can also be set or canceled separately for an event
using
+config terms. For example: 'cycles/flightrecorder/' and
'instructions/no-flightrecorder/'.
Implies --tail-synthesize.
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index f4d9fc5..315ea09 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1489,7 +1489,7 @@ static struct option __record_options[] = {
"child tasks do not inherit counters"),
OPT_BOOLEAN(0, "tail-synthesize", &record.opts.tail_synthesize,
"synthesize non-sample events at the end of output"),
- OPT_BOOLEAN(0, "overwrite", &record.opts.overwrite, "use overwrite
mode"),
+ OPT_BOOLEAN(0, "flight-recoder", &record.opts.flight_recorder, "use
flight recoder mode"),
OPT_UINTEGER('F', "freq", &record.opts.user_freq, "profile at this
frequency"),
OPT_CALLBACK('m', "mmap-pages", &record.opts, "pages[,pages]",
"number of mmap data pages and AUX area tracing mmap
pages",
@@ -1733,7 +1733,7 @@ int cmd_record(int argc, const char **argv)
}
}
- if (record.opts.overwrite)
+ if (record.opts.flight_recorder)
record.opts.tail_synthesize = true;
if (rec->evlist->nr_entries == 0 &&
diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index fbb0a9c..a7f7618 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -57,7 +57,7 @@ struct record_opts {
bool all_kernel;
bool all_user;
bool tail_synthesize;
- bool overwrite;
+ bool flight_recorder;
bool ignore_missing_thread;
unsigned int freq;
unsigned int mmap_pages;
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index f894893..0e1e8e8 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -772,8 +772,8 @@ static void apply_config_terms(struct perf_evsel *evsel,
*/
attr->inherit = term->val.inherit ? 1 : 0;
break;
- case PERF_EVSEL__CONFIG_TERM_OVERWRITE:
- attr->write_backward = term->val.overwrite ? 1 : 0;
+ case PERF_EVSEL__CONFIG_TERM_FLIGHTRECORDER:
+ attr->write_backward = term->val.flightrecorder ? 1 : 0;
break;
default:
break;
@@ -856,7 +856,7 @@ void perf_evsel__config(struct perf_evsel *evsel, struct
record_opts *opts,
attr->sample_id_all = perf_missing_features.sample_id_all ? 0 : 1;
attr->inherit = !opts->no_inherit;
- attr->write_backward = opts->overwrite ? 1 : 0;
+ attr->write_backward = opts->flight_recorder ? 1 : 0;
perf_evsel__set_sample_bit(evsel, IP);
perf_evsel__set_sample_bit(evsel, TID);
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 64782b1..115b637 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -45,7 +45,7 @@ enum {
PERF_EVSEL__CONFIG_TERM_STACK_USER,
PERF_EVSEL__CONFIG_TERM_INHERIT,
PERF_EVSEL__CONFIG_TERM_MAX_STACK,
- PERF_EVSEL__CONFIG_TERM_OVERWRITE,
+ PERF_EVSEL__CONFIG_TERM_FLIGHTRECORDER,
PERF_EVSEL__CONFIG_TERM_DRV_CFG,
PERF_EVSEL__CONFIG_TERM_BRANCH,
PERF_EVSEL__CONFIG_TERM_MAX,
@@ -63,7 +63,7 @@ struct perf_evsel_config_term {
u64 stack_user;
int max_stack;
bool inherit;
- bool overwrite;
+ bool flightrecorder;
char *branch;
} val;
};
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 04f35db..61ae3d3 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -914,8 +914,8 @@ static const char
*config_term_names[__PARSE_EVENTS__TERM_TYPE_NR] = {
[PARSE_EVENTS__TERM_TYPE_NOINHERIT] = "no-inherit",
[PARSE_EVENTS__TERM_TYPE_INHERIT] = "inherit",
[PARSE_EVENTS__TERM_TYPE_MAX_STACK] = "max-stack",
- [PARSE_EVENTS__TERM_TYPE_OVERWRITE] = "overwrite",
- [PARSE_EVENTS__TERM_TYPE_NOOVERWRITE] = "no-overwrite",
+ [PARSE_EVENTS__TERM_TYPE_FLIGHTRECORDER] = "flightrecorder",
+ [PARSE_EVENTS__TERM_TYPE_NOFLIGHTRECORDER] = "no-flightrecorder",
[PARSE_EVENTS__TERM_TYPE_DRV_CFG] = "driver-config",
};
@@ -1013,10 +1013,10 @@ do {
\
case PARSE_EVENTS__TERM_TYPE_NOINHERIT:
CHECK_TYPE_VAL(NUM);
break;
- case PARSE_EVENTS__TERM_TYPE_OVERWRITE:
+ case PARSE_EVENTS__TERM_TYPE_FLIGHTRECORDER:
CHECK_TYPE_VAL(NUM);
break;
- case PARSE_EVENTS__TERM_TYPE_NOOVERWRITE:
+ case PARSE_EVENTS__TERM_TYPE_NOFLIGHTRECORDER:
CHECK_TYPE_VAL(NUM);
break;
case PARSE_EVENTS__TERM_TYPE_NAME:
@@ -1072,8 +1072,8 @@ static int config_term_tracepoint(struct perf_event_attr
*attr,
case PARSE_EVENTS__TERM_TYPE_INHERIT:
case PARSE_EVENTS__TERM_TYPE_NOINHERIT:
case PARSE_EVENTS__TERM_TYPE_MAX_STACK:
- case PARSE_EVENTS__TERM_TYPE_OVERWRITE:
- case PARSE_EVENTS__TERM_TYPE_NOOVERWRITE:
+ case PARSE_EVENTS__TERM_TYPE_FLIGHTRECORDER:
+ case PARSE_EVENTS__TERM_TYPE_NOFLIGHTRECORDER:
return config_term_common(attr, term, err);
default:
if (err) {
@@ -1149,11 +1149,11 @@ do {
\
case PARSE_EVENTS__TERM_TYPE_MAX_STACK:
ADD_CONFIG_TERM(MAX_STACK, max_stack, term->val.num);
break;
- case PARSE_EVENTS__TERM_TYPE_OVERWRITE:
- ADD_CONFIG_TERM(OVERWRITE, overwrite, term->val.num ? 1
: 0);
+ case PARSE_EVENTS__TERM_TYPE_FLIGHTRECORDER:
+ ADD_CONFIG_TERM(FLIGHTRECORDER, flightrecorder,
term->val.num ? 1 : 0);
break;
- case PARSE_EVENTS__TERM_TYPE_NOOVERWRITE:
- ADD_CONFIG_TERM(OVERWRITE, overwrite, term->val.num ? 0
: 1);
+ case PARSE_EVENTS__TERM_TYPE_NOFLIGHTRECORDER:
+ ADD_CONFIG_TERM(FLIGHTRECORDER, flightrecorder,
term->val.num ? 0 : 1);
break;
case PARSE_EVENTS__TERM_TYPE_DRV_CFG:
ADD_CONFIG_TERM(DRV_CFG, drv_cfg, term->val.str);
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index 3909ca0..cd0b4eae 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -70,8 +70,8 @@ enum {
PARSE_EVENTS__TERM_TYPE_NOINHERIT,
PARSE_EVENTS__TERM_TYPE_INHERIT,
PARSE_EVENTS__TERM_TYPE_MAX_STACK,
- PARSE_EVENTS__TERM_TYPE_NOOVERWRITE,
- PARSE_EVENTS__TERM_TYPE_OVERWRITE,
+ PARSE_EVENTS__TERM_TYPE_NOFLIGHTRECORDER,
+ PARSE_EVENTS__TERM_TYPE_FLIGHTRECORDER,
PARSE_EVENTS__TERM_TYPE_DRV_CFG,
__PARSE_EVENTS__TERM_TYPE_NR,
};
diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
index 38a42bd..7710d6d 100644
--- a/tools/perf/util/parse-events.l
+++ b/tools/perf/util/parse-events.l
@@ -251,8 +251,8 @@ stack-size { return term(yyscanner,
PARSE_EVENTS__TERM_TYPE_STACKSIZE); }
max-stack { return term(yyscanner,
PARSE_EVENTS__TERM_TYPE_MAX_STACK); }
inherit { return term(yyscanner,
PARSE_EVENTS__TERM_TYPE_INHERIT); }
no-inherit { return term(yyscanner,
PARSE_EVENTS__TERM_TYPE_NOINHERIT); }
-overwrite { return term(yyscanner,
PARSE_EVENTS__TERM_TYPE_OVERWRITE); }
-no-overwrite { return term(yyscanner,
PARSE_EVENTS__TERM_TYPE_NOOVERWRITE); }
+flightrecorder { return term(yyscanner,
PARSE_EVENTS__TERM_TYPE_FLIGHTRECORDER); }
+no-flightrecorder { return term(yyscanner,
PARSE_EVENTS__TERM_TYPE_NOFLIGHTRECORDER); }
, { return ','; }
"/" { BEGIN(INITIAL); return '/'; }
{name_minus} { return str(yyscanner, PE_NAME); }
--
2.10.1
