Add 'snapshot' control command to create an AUX area tracing snapshot
the same as if sending SIGUSR2. The advantage of the FIFO is that access
is governed by access to the FIFO.
Example:
$ mkfifo perf.control
$ mkfifo perf.ack
$ cat perf.ack &
[1] 15235
$ sudo ~/bin/perf record --control fifo:perf.control,perf.ack -S -e intel_pt//u -- sleep 60 &
[2] 15243
$ ps -e | grep perf
15244 pts/1 00:00:00 perf
$ kill -USR2 15244
bash: kill: (15244) - Operation not permitted
$ echo snapshot > perf.control
ack
$
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/20200901093758.32293-6-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
--control=fd:ctl-fd[,ack-fd]::
ctl-fifo / ack-fifo are opened and used as ctl-fd / ack-fd as follows.
Listen on ctl-fd descriptor for command to control measurement ('enable': enable events,
-'disable': disable events). Measurements can be started with events disabled using
---delay=-1 option. Optionally send control command completion ('ack\n') to ack-fd descriptor
-to synchronize with the controlling process. Example of bash shell script to enable and
-disable events during measurements:
+'disable': disable events, 'snapshot': AUX area tracing snapshot). Measurements can be
+started with events disabled using --delay=-1 option. Optionally send control command
+completion ('ack\n') to ack-fd descriptor to synchronize with the controlling process.
+Example of bash shell script to enable and disable events during measurements:
#!/bin/bash
return 0;
}
+static void hit_auxtrace_snapshot_trigger(struct record *rec)
+{
+ if (trigger_is_ready(&auxtrace_snapshot_trigger)) {
+ trigger_hit(&auxtrace_snapshot_trigger);
+ auxtrace_record__snapshot_started = 1;
+ if (auxtrace_record__snapshot_start(rec->itr))
+ trigger_error(&auxtrace_snapshot_trigger);
+ }
+}
+
static int __cmd_record(struct record *rec, int argc, const char **argv)
{
int err;
case EVLIST_CTL_CMD_DISABLE:
pr_info(EVLIST_DISABLED_MSG);
break;
+ case EVLIST_CTL_CMD_SNAPSHOT:
+ hit_auxtrace_snapshot_trigger(rec);
+ evlist__ctlfd_ack(rec->evlist);
+ break;
case EVLIST_CTL_CMD_ACK:
case EVLIST_CTL_CMD_UNSUPPORTED:
default:
parse_libpfm_events_option),
#endif
OPT_CALLBACK(0, "control", &record.opts, "fd:ctl-fd[,ack-fd] or fifo:ctl-fifo[,ack-fifo]",
- "Listen on ctl-fd descriptor for command to control measurement ('enable': enable events, 'disable': disable events).\n"
+ "Listen on ctl-fd descriptor for command to control measurement ('enable': enable events, 'disable': disable events,\n"
+ "\t\t\t 'snapshot': AUX area tracing snapshot).\n"
"\t\t\t Optionally send control command completion ('ack\\n') to ack-fd descriptor.\n"
"\t\t\t Alternatively, ctl-fifo / ack-fifo will be opened and used as ctl-fd / ack-fd.",
parse_control_option),
{
struct record *rec = &record;
- if (trigger_is_ready(&auxtrace_snapshot_trigger)) {
- trigger_hit(&auxtrace_snapshot_trigger);
- auxtrace_record__snapshot_started = 1;
- if (auxtrace_record__snapshot_start(record.itr))
- trigger_error(&auxtrace_snapshot_trigger);
- }
+ hit_auxtrace_snapshot_trigger(rec);
if (switch_output_signal(rec))
trigger_hit(&switch_output_trigger);
process_interval();
pr_info(EVLIST_DISABLED_MSG);
break;
+ case EVLIST_CTL_CMD_SNAPSHOT:
case EVLIST_CTL_CMD_ACK:
case EVLIST_CTL_CMD_UNSUPPORTED:
default:
} else if (!strncmp(cmd_data, EVLIST_CTL_CMD_DISABLE_TAG,
(sizeof(EVLIST_CTL_CMD_DISABLE_TAG)-1))) {
*cmd = EVLIST_CTL_CMD_DISABLE;
+ } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_SNAPSHOT_TAG,
+ (sizeof(EVLIST_CTL_CMD_SNAPSHOT_TAG)-1))) {
+ *cmd = EVLIST_CTL_CMD_SNAPSHOT;
+ pr_debug("is snapshot\n");
}
}
return bytes_read ? (int)bytes_read : err;
}
-static int evlist__ctlfd_ack(struct evlist *evlist)
+int evlist__ctlfd_ack(struct evlist *evlist)
{
int err;
case EVLIST_CTL_CMD_DISABLE:
evlist__disable(evlist);
break;
+ case EVLIST_CTL_CMD_SNAPSHOT:
+ break;
case EVLIST_CTL_CMD_ACK:
case EVLIST_CTL_CMD_UNSUPPORTED:
default:
pr_debug("ctlfd: unsupported %d\n", *cmd);
break;
}
- if (!(*cmd == EVLIST_CTL_CMD_ACK || *cmd == EVLIST_CTL_CMD_UNSUPPORTED))
+ if (!(*cmd == EVLIST_CTL_CMD_ACK || *cmd == EVLIST_CTL_CMD_UNSUPPORTED ||
+ *cmd == EVLIST_CTL_CMD_SNAPSHOT))
evlist__ctlfd_ack(evlist);
}
}
#define EVLIST_CTL_CMD_ENABLE_TAG "enable"
#define EVLIST_CTL_CMD_DISABLE_TAG "disable"
#define EVLIST_CTL_CMD_ACK_TAG "ack\n"
+#define EVLIST_CTL_CMD_SNAPSHOT_TAG "snapshot"
#define EVLIST_CTL_CMD_MAX_LEN 64
EVLIST_CTL_CMD_UNSUPPORTED = 0,
EVLIST_CTL_CMD_ENABLE,
EVLIST_CTL_CMD_DISABLE,
- EVLIST_CTL_CMD_ACK
+ EVLIST_CTL_CMD_ACK,
+ EVLIST_CTL_CMD_SNAPSHOT,
};
int evlist__parse_control(const char *str, int *ctl_fd, int *ctl_fd_ack, bool *ctl_fd_close);
int evlist__finalize_ctlfd(struct evlist *evlist);
bool evlist__ctlfd_initialized(struct evlist *evlist);
int evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd);
+int evlist__ctlfd_ack(struct evlist *evlist);
#define EVLIST_ENABLED_MSG "Events enabled\n"
#define EVLIST_DISABLED_MSG "Events disabled\n"