On Sat, Apr 10, 2021 at 01:00:42PM +0800, Leo Yan wrote:
> During the recording phase, "perf record" tool synthesizes event
> PERF_RECORD_TIME_CONV for the hardware clock parameters and saves the
> event into the data file.
>
> Afterwards, when processing the data file, the event TIME_CONV will be
> processed at the very early time and is stored into session context.
>
> This patch extracts these parameters from the session context and saves
> into the structure "spe->tc" with the type perf_tsc_conversion, so that
> the parameters are ready for conversion between clock counter and time
> stamp.
>
> Signed-off-by: Leo Yan <leo....@linaro.org>
[...]
> ---
> tools/perf/util/arm-spe.c | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
>
> diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c
> index 2539d4baec44..b48816d5c0b4 100644
> --- a/tools/perf/util/arm-spe.c
> +++ b/tools/perf/util/arm-spe.c
> @@ -26,6 +26,7 @@
> #include "symbol.h"
> #include "thread.h"
> #include "thread-stack.h"
> +#include "tsc.h"
> #include "tool.h"
> #include "util/synthetic-events.h"
>
> @@ -45,6 +46,8 @@ struct arm_spe {
> struct machine *machine;
> u32 pmu_type;
>
> + struct perf_tsc_conversion tc;
> +
> u8 timeless_decoding;
> u8 data_queued;
>
> @@ -1027,6 +1030,22 @@ int arm_spe_process_auxtrace_info(union perf_event
> *event,
> spe->pmu_type = auxtrace_info->priv[ARM_SPE_PMU_TYPE];
>
> spe->timeless_decoding = arm_spe__is_timeless_decoding(spe);
> +
> + /*
> + * The synthesized event PERF_RECORD_TIME_CONV has been handled
> + * ahead and the parameters for hardware clock are stored in
> + * the session context. Passes these parameters to the structure
> + * perf_tsc_conversion in "spe->tc", which is used for later
> + * conversion between clock counter and timestamp.
> + */
> + spe->tc.time_shift = session->time_conv.time_shift;
> + spe->tc.time_mult = session->time_conv.time_mult;
> + spe->tc.time_zero = session->time_conv.time_zero;
> + spe->tc.time_cycles = session->time_conv.time_cycles;
> + spe->tc.time_mask = session->time_conv.time_mask;
> + spe->tc.cap_user_time_zero = session->time_conv.cap_user_time_zero;
> + spe->tc.cap_user_time_short = session->time_conv.cap_user_time_short;
As Adrain suggested, this patch also should check the size of event
PERF_RECORD_TIME_CONV for backwards-compability. I will send a new
patch set for this.
Thanks,
Leo
> spe->auxtrace.process_event = arm_spe_process_event;
> spe->auxtrace.process_auxtrace_event = arm_spe_process_auxtrace_event;
> spe->auxtrace.flush_events = arm_spe_flush;
> --
> 2.25.1
>
