Re: [PATCH 3/6] perf cs-etm: Only setup queues when they are modified

From: Mathieu Poirier
Date: Mon Jul 19 2021 - 16:27:17 EST


On Tue, Jul 13, 2021 at 04:40:05PM +0100, James Clark wrote:
> Continually creating queues in cs_etm__process_event() is unnecessary.
> They only need to be created when a buffer for a new CPU or thread is
> encountered. This can be in two places, when building the queues in
> advance in cs_etm__process_auxtrace_info(), or in
> cs_etm__process_auxtrace_event() when data_queued is false and the
> index wasn't available (pipe mode).
>
> This change will allow the 'formatted' decoder setting to applied when
> iterating over aux records in a later commit.
>
> Signed-off-by: James Clark <james.clark@xxxxxxx>
> ---
> tools/perf/util/cs-etm.c | 54 +++++++++++-----------------------------
> 1 file changed, 14 insertions(+), 40 deletions(-)

Reviewed-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>

>
> diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
> index 426e99c07ca9..2d07e52ffd3c 100644
> --- a/tools/perf/util/cs-etm.c
> +++ b/tools/perf/util/cs-etm.c
> @@ -96,7 +96,6 @@ struct cs_etm_queue {
> /* RB tree for quick conversion between traceID and metadata pointers */
> static struct intlist *traceid_list;
>
> -static int cs_etm__update_queues(struct cs_etm_auxtrace *etm);
> static int cs_etm__process_queues(struct cs_etm_auxtrace *etm);
> static int cs_etm__process_timeless_queues(struct cs_etm_auxtrace *etm,
> pid_t tid);
> @@ -564,7 +563,6 @@ static void cs_etm__dump_event(struct cs_etm_auxtrace *etm,
> static int cs_etm__flush_events(struct perf_session *session,
> struct perf_tool *tool)
> {
> - int ret;
> struct cs_etm_auxtrace *etm = container_of(session->auxtrace,
> struct cs_etm_auxtrace,
> auxtrace);
> @@ -574,11 +572,6 @@ static int cs_etm__flush_events(struct perf_session *session,
> if (!tool->ordered_events)
> return -EINVAL;
>
> - ret = cs_etm__update_queues(etm);
> -
> - if (ret < 0)
> - return ret;
> -
> if (etm->timeless_decoding)
> return cs_etm__process_timeless_queues(etm, -1);
>
> @@ -898,30 +891,6 @@ static int cs_etm__queue_first_cs_timestamp(struct cs_etm_auxtrace *etm,
> return ret;
> }
>
> -static int cs_etm__setup_queues(struct cs_etm_auxtrace *etm)
> -{
> - unsigned int i;
> - int ret;
> -
> - for (i = 0; i < etm->queues.nr_queues; i++) {
> - ret = cs_etm__setup_queue(etm, &etm->queues.queue_array[i], i);
> - if (ret)
> - return ret;
> - }
> -
> - return 0;
> -}
> -
> -static int cs_etm__update_queues(struct cs_etm_auxtrace *etm)
> -{
> - if (etm->queues.new_data) {
> - etm->queues.new_data = false;
> - return cs_etm__setup_queues(etm);
> - }
> -
> - return 0;
> -}
> -
> static inline
> void cs_etm__copy_last_branch_rb(struct cs_etm_queue *etmq,
> struct cs_etm_traceid_queue *tidq)
> @@ -2395,7 +2364,6 @@ static int cs_etm__process_event(struct perf_session *session,
> struct perf_sample *sample,
> struct perf_tool *tool)
> {
> - int err = 0;
> u64 sample_kernel_timestamp;
> struct cs_etm_auxtrace *etm = container_of(session->auxtrace,
> struct cs_etm_auxtrace,
> @@ -2414,12 +2382,6 @@ static int cs_etm__process_event(struct perf_session *session,
> else
> sample_kernel_timestamp = 0;
>
> - if (sample_kernel_timestamp || etm->timeless_decoding) {
> - err = cs_etm__update_queues(etm);
> - if (err)
> - return err;
> - }
> -
> /*
> * Don't wait for cs_etm__flush_events() in per-thread/timeless mode to start the decode. We
> * need the tid of the PERF_RECORD_EXIT event to assign to the synthesised samples because
> @@ -2476,6 +2438,7 @@ static int cs_etm__process_auxtrace_event(struct perf_session *session,
> int fd = perf_data__fd(session->data);
> bool is_pipe = perf_data__is_pipe(session->data);
> int err;
> + int idx = event->auxtrace.idx;
>
> if (is_pipe)
> data_offset = 0;
> @@ -2490,6 +2453,11 @@ static int cs_etm__process_auxtrace_event(struct perf_session *session,
> if (err)
> return err;
>
> + err = cs_etm__setup_queue(etm, &etm->queues.queue_array[idx],
> + idx);
> + if (err)
> + return err;
> +
> if (dump_trace)
> if (auxtrace_buffer__get_data(buffer, fd)) {
> cs_etm__dump_event(etm, buffer);
> @@ -2732,6 +2700,7 @@ static int cs_etm__queue_aux_fragment(struct perf_session *session, off_t file_o
> struct perf_record_auxtrace *auxtrace_event;
> union perf_event auxtrace_fragment;
> __u64 aux_offset, aux_size;
> + __u32 idx;
>
> struct cs_etm_auxtrace *etm = container_of(session->auxtrace,
> struct cs_etm_auxtrace,
> @@ -2793,8 +2762,13 @@ static int cs_etm__queue_aux_fragment(struct perf_session *session, off_t file_o
>
> pr_debug3("CS ETM: Queue buffer size: %#"PRI_lx64" offset: %#"PRI_lx64
> " tid: %d cpu: %d\n", aux_size, aux_offset, sample->tid, sample->cpu);
> - return auxtrace_queues__add_event(&etm->queues, session, &auxtrace_fragment,
> - file_offset, NULL);
> + err = auxtrace_queues__add_event(&etm->queues, session, &auxtrace_fragment,
> + file_offset, NULL);
> + if (err)
> + return err;
> +
> + idx = auxtrace_event->idx;
> + return cs_etm__setup_queue(etm, &etm->queues.queue_array[idx], idx);
> }
>
> /* Wasn't inside this buffer, but there were no parse errors. 1 == 'not found' */
> --
> 2.28.0
>