On 2/09/20 8:03 pm, Alexey Budankov wrote: > > On 01.09.2020 12:37, Adrian Hunter wrote: >> 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 <[email protected]> >> --- >> tools/perf/Documentation/perf-record.txt | 8 ++++---- >> tools/perf/builtin-record.c | 24 +++++++++++++++++------- >> tools/perf/builtin-stat.c | 1 + >> tools/perf/util/evlist.c | 11 +++++++++-- >> tools/perf/util/evlist.h | 5 ++++- >> 5 files changed, 35 insertions(+), 14 deletions(-) >> >> diff --git a/tools/perf/Documentation/perf-record.txt >> b/tools/perf/Documentation/perf-record.txt >> index 2ffc1196d2b8..588e6191bf39 100644 >> --- a/tools/perf/Documentation/perf-record.txt >> +++ b/tools/perf/Documentation/perf-record.txt >> @@ -631,10 +631,10 @@ endif::HAVE_LIBPFM[] >> --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 >> >> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c >> index 117dd180f780..476b34ff3152 100644 >> --- a/tools/perf/builtin-record.c >> +++ b/tools/perf/builtin-record.c >> @@ -1593,6 +1593,16 @@ static int record__init_clock(struct record *rec) >> 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; >> @@ -1937,6 +1947,10 @@ static int __cmd_record(struct record *rec, int argc, >> const char **argv) >> case EVLIST_CTL_CMD_DISABLE: >> pr_info(EVLIST_DISABLED_MSG); >> break; >> + case EVLIST_CTL_CMD_SNAPSHOT: >> + hit_auxtrace_snapshot_trigger(rec); > > Could possibly print a messages to console that snapshot taking has started, > similar to enabling and disabling of events.
There is a an existing debug print for snapshots, and the ack fifo of course. So I am going to leave that for now. > > Acked-by: Alexei Budankov <[email protected]> > > Regards, > Alexei > >> + evlist__ctlfd_ack(rec->evlist); >> + break; >> case EVLIST_CTL_CMD_ACK: >> case EVLIST_CTL_CMD_UNSUPPORTED: >> default: >> @@ -2589,7 +2603,8 @@ static struct option __record_options[] = { >> 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), >> @@ -2842,12 +2857,7 @@ 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; >> - 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); >> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c >> index 6170226d44f9..21424ed0734b 100644 >> --- a/tools/perf/builtin-stat.c >> +++ b/tools/perf/builtin-stat.c >> @@ -578,6 +578,7 @@ static void process_evlist(struct evlist *evlist, >> unsigned int interval) >> process_interval(); >> pr_info(EVLIST_DISABLED_MSG); >> break; >> + case EVLIST_CTL_CMD_SNAPSHOT: >> case EVLIST_CTL_CMD_ACK: >> case EVLIST_CTL_CMD_UNSUPPORTED: >> default: >> diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c >> index b74e85bc683e..8cd53dbb0357 100644 >> --- a/tools/perf/util/evlist.c >> +++ b/tools/perf/util/evlist.c >> @@ -1885,13 +1885,17 @@ static int evlist__ctlfd_recv(struct evlist *evlist, >> enum evlist_ctl_cmd *cmd, >> } 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; >> >> @@ -1927,13 +1931,16 @@ int evlist__ctlfd_process(struct evlist *evlist, >> enum evlist_ctl_cmd *cmd) >> 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); >> } >> } >> diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h >> index a5678eb5ee60..91d1da6e1fe3 100644 >> --- a/tools/perf/util/evlist.h >> +++ b/tools/perf/util/evlist.h >> @@ -363,6 +363,7 @@ struct evsel *perf_evlist__reset_weak_group(struct >> evlist *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 >> >> @@ -370,7 +371,8 @@ enum evlist_ctl_cmd { >> 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); >> @@ -378,6 +380,7 @@ int evlist__initialize_ctlfd(struct evlist *evlist, int >> ctl_fd, int ctl_fd_ack); >> 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" >>
