From: Alexander Shishkin <alexander.shish...@linux.intel.com> It is sometimes useful to generate a snapshot when perf record exits; I've been using a wrapper script around the workload that would do a killall -USR2 perf when the workload exits.
This patch makes it easier and also works when perf record is attached to a pre-existing task. A new snapshot option 'e' can be specified in -S to enable this behavior: root@elsewhere:~# perf record -e intel_pt// -Se sleep 1 [ perf record: Woken up 2 times to write data ] [ perf record: Captured and wrote 0.085 MB perf.data ] Co-developed-by: Adrian Hunter <adrian.hun...@intel.com> Signed-off-by: Alexander Shishkin <alexander.shish...@linux.intel.com> Cc: Peter Zijlstra <pet...@infradead.org> Link: http://lkml.kernel.org/r/20190806144101.62892-1-alexander.shish...@linux.intel.com [ Fixed up !HAVE_AUXTRACE_SUPPORT build in builtin-record.c, adding 2 missing __maybe_unused ] Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/Documentation/perf-record.txt | 11 ++++++-- tools/perf/builtin-record.c | 35 +++++++++++++++++++++--- tools/perf/perf.h | 1 + tools/perf/util/auxtrace.c | 14 ++++++++-- tools/perf/util/auxtrace.h | 2 +- 5 files changed, 53 insertions(+), 10 deletions(-) diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index 15e0fa87241b..d5e58e0a2bca 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -422,9 +422,14 @@ CLOCK_BOOTTIME, CLOCK_REALTIME and CLOCK_TAI. -S:: --snapshot:: Select AUX area tracing Snapshot Mode. This option is valid only with an -AUX area tracing event. Optionally the number of bytes to capture per -snapshot can be specified. In Snapshot Mode, trace data is captured only when -signal SIGUSR2 is received. +AUX area tracing event. Optionally, certain snapshot capturing parameters +can be specified in a string that follows this option: + 'e': take one last snapshot on exit; guarantees that there is at least one + snapshot in the output file; + <size>: if the PMU supports this, specify the desired snapshot size. + +In Snapshot Mode trace data is captured only when signal SIGUSR2 is received +and on exit if the above 'e' option is given. --proc-map-timeout:: When processing pre-existing threads /proc/XXX/mmap, it may take a long time, diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index d31d7a5a1be3..f71631f2bcb5 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -613,19 +613,35 @@ static int record__auxtrace_read_snapshot_all(struct record *rec) return rc; } -static void record__read_auxtrace_snapshot(struct record *rec) +static void record__read_auxtrace_snapshot(struct record *rec, bool on_exit) { pr_debug("Recording AUX area tracing snapshot\n"); if (record__auxtrace_read_snapshot_all(rec) < 0) { trigger_error(&auxtrace_snapshot_trigger); } else { - if (auxtrace_record__snapshot_finish(rec->itr)) + if (auxtrace_record__snapshot_finish(rec->itr, on_exit)) trigger_error(&auxtrace_snapshot_trigger); else trigger_ready(&auxtrace_snapshot_trigger); } } +static int record__auxtrace_snapshot_exit(struct record *rec) +{ + if (trigger_is_error(&auxtrace_snapshot_trigger)) + return 0; + + if (!auxtrace_record__snapshot_started && + auxtrace_record__snapshot_start(rec->itr)) + return -1; + + record__read_auxtrace_snapshot(rec, true); + if (trigger_is_error(&auxtrace_snapshot_trigger)) + return -1; + + return 0; +} + static int record__auxtrace_init(struct record *rec) { int err; @@ -654,7 +670,8 @@ int record__auxtrace_mmap_read(struct record *rec __maybe_unused, } static inline -void record__read_auxtrace_snapshot(struct record *rec __maybe_unused) +void record__read_auxtrace_snapshot(struct record *rec __maybe_unused, + bool on_exit __maybe_unused) { } @@ -664,6 +681,12 @@ int auxtrace_record__snapshot_start(struct auxtrace_record *itr __maybe_unused) return 0; } +static inline +int record__auxtrace_snapshot_exit(struct record *rec __maybe_unused) +{ + return 0; +} + static int record__auxtrace_init(struct record *rec __maybe_unused) { return 0; @@ -1536,7 +1559,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) if (auxtrace_record__snapshot_started) { auxtrace_record__snapshot_started = 0; if (!trigger_is_error(&auxtrace_snapshot_trigger)) - record__read_auxtrace_snapshot(rec); + record__read_auxtrace_snapshot(rec, false); if (trigger_is_error(&auxtrace_snapshot_trigger)) { pr_err("AUX area tracing snapshot failed\n"); err = -1; @@ -1609,9 +1632,13 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) disabled = true; } } + trigger_off(&auxtrace_snapshot_trigger); trigger_off(&switch_output_trigger); + if (opts->auxtrace_snapshot_on_exit) + record__auxtrace_snapshot_exit(rec); + if (forks && workload_exec_errno) { char msg[STRERR_BUFSIZE]; const char *emsg = str_error_r(workload_exec_errno, msg, sizeof(msg)); diff --git a/tools/perf/perf.h b/tools/perf/perf.h index 74d0124d38f3..dc0a7a237887 100644 --- a/tools/perf/perf.h +++ b/tools/perf/perf.h @@ -57,6 +57,7 @@ struct record_opts { bool running_time; bool full_auxtrace; bool auxtrace_snapshot_mode; + bool auxtrace_snapshot_on_exit; bool record_namespaces; bool record_switch_events; bool all_kernel; diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c index 65728cdeefb6..72ce4c5e7c78 100644 --- a/tools/perf/util/auxtrace.c +++ b/tools/perf/util/auxtrace.c @@ -539,9 +539,9 @@ int auxtrace_record__snapshot_start(struct auxtrace_record *itr) return 0; } -int auxtrace_record__snapshot_finish(struct auxtrace_record *itr) +int auxtrace_record__snapshot_finish(struct auxtrace_record *itr, bool on_exit) { - if (itr && itr->snapshot_finish) + if (!on_exit && itr && itr->snapshot_finish) return itr->snapshot_finish(itr); return 0; } @@ -577,6 +577,16 @@ int auxtrace_parse_snapshot_options(struct auxtrace_record *itr, if (!str) return 0; + /* PMU-agnostic options */ + switch (*str) { + case 'e': + opts->auxtrace_snapshot_on_exit = true; + str++; + break; + default: + break; + } + if (itr) return itr->parse_snapshot_options(itr, opts, str); diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h index 17eb04a1da4d..8ccabacd0b11 100644 --- a/tools/perf/util/auxtrace.h +++ b/tools/perf/util/auxtrace.h @@ -499,7 +499,7 @@ int auxtrace_record__info_fill(struct auxtrace_record *itr, size_t priv_size); void auxtrace_record__free(struct auxtrace_record *itr); int auxtrace_record__snapshot_start(struct auxtrace_record *itr); -int auxtrace_record__snapshot_finish(struct auxtrace_record *itr); +int auxtrace_record__snapshot_finish(struct auxtrace_record *itr, bool on_exit); int auxtrace_record__find_snapshot(struct auxtrace_record *itr, int idx, struct auxtrace_mmap *mm, unsigned char *data, u64 *head, u64 *old); -- 2.21.0
