From 78efa7b411450a534e9d326cdf5578f681c73988 Mon Sep 17 00:00:00 2001 From: Leo Yan Date: Sat, 14 Oct 2023 15:41:59 +0800 Subject: [PATCH] perf cs-etm: Respect timestamp option When users pass the option '--timestamp' or '-T' in the record command, all events will set the PERF_SAMPLE_TIME bit in the attribution. In this case, the AUX event will record the kernel timestamp, but it doesn't mean Arm CoreSight enables timestamp packets in its hardware tracing. If the option '--timestamp' or '-T' is set, this patch always enables Arm CoreSight timestamp, as a result, the bit 28 in event's config is to be set. Before: # perf record -e cs_etm// --per-thread --timestamp -- ls # perf script --header-only ... # event : name = cs_etm//, , id = { 69 }, type = 12, size = 136, config = 0, { sample_period, sample_freq } = 1, sample_type = IP|TID|TIME|CPU|IDENTIFIER, read_format = ID|LOST, disabled = 1, enable_on_exec = 1, sample_id_all = 1, exclude_guest = 1 ... After: # perf record -e cs_etm// --per-thread --timestamp -- ls # perf script --header-only ... # event : name = cs_etm//, , id = { 49 }, type = 12, size = 136, config = 0x10000000, { sample_period, sample_freq } = 1, sample_type = IP|TID|TIME|CPU|IDENTIFIER, read_format = ID|LOST, disabled = 1, enable_on_exec = 1, sample_id_all = 1, exclude_guest = 1 ... Signed-off-by: Leo Yan Reviewed-by: James Clark Acked-by: Suzuki K Poulose Cc: Will Deacon Cc: Mike Leach Cc: Alexander Shishkin Cc: John Garry Cc: linux-arm-kernel@lists.infradead.org Cc: coresight@lists.linaro.org Link: https://lore.kernel.org/r/20231014074159.1667880-3-leo.yan@linaro.org Signed-off-by: Namhyung Kim --- tools/perf/arch/arm/util/cs-etm.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c index 39ec6cae91ed..2cf873d71dff 100644 --- a/tools/perf/arch/arm/util/cs-etm.c +++ b/tools/perf/arch/arm/util/cs-etm.c @@ -442,6 +442,15 @@ static int cs_etm_recording_options(struct auxtrace_record *itr, "contextid", 1); } + /* + * When the option '--timestamp' or '-T' is enabled, the PERF_SAMPLE_TIME + * bit is set for all events. In this case, always enable Arm CoreSight + * timestamp tracing. + */ + if (opts->sample_time_set) + evsel__set_config_if_unset(cs_etm_pmu, cs_etm_evsel, + "timestamp", 1); + /* Add dummy event to keep tracking */ err = parse_event(evlist, "dummy:u"); if (err)