Messages in this thread | | | Subject | Re: [PATCH v1 1/3] perf jit: Let convert_timestamp() to be backwards-compatible | From | Adrian Hunter <> | Date | Mon, 26 Apr 2021 08:55:19 +0300 |
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On 12/04/21 11:34 am, Leo Yan wrote: > Commit d110162cafc8 ("perf tsc: Support cap_user_time_short for event > TIME_CONV") supports the extended parameters for event TIME_CONV, but it > broke the backwards compatibility, so any perf data file with old event > format fails to convert timestamp. > > For the backwards-compatibility, this patch checks the event size, if > the event size confirms the extended parameters are supported in the > event TIME_CONV, then copies these parameters. > > Fixes: d110162cafc8 ("perf tsc: Support cap_user_time_short for event TIME_CONV") > Signed-off-by: Leo Yan <leo.yan@linaro.org>
Perhaps could make use of a helper like the one described in my comments for patch 2. Nevertheless:
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
> --- > tools/perf/util/jitdump.c | 31 +++++++++++++++++++++---------- > 1 file changed, 21 insertions(+), 10 deletions(-) > > diff --git a/tools/perf/util/jitdump.c b/tools/perf/util/jitdump.c > index 9760d8e7b386..67b514c38a43 100644 > --- a/tools/perf/util/jitdump.c > +++ b/tools/perf/util/jitdump.c > @@ -396,21 +396,32 @@ static pid_t jr_entry_tid(struct jit_buf_desc *jd, union jr_entry *jr) > > static uint64_t convert_timestamp(struct jit_buf_desc *jd, uint64_t timestamp) > { > - struct perf_tsc_conversion tc; > + struct perf_tsc_conversion tc = { 0 }; > + struct perf_record_time_conv *time_conv = &jd->session->time_conv; > > if (!jd->use_arch_timestamp) > return timestamp; > > - tc.time_shift = jd->session->time_conv.time_shift; > - tc.time_mult = jd->session->time_conv.time_mult; > - tc.time_zero = jd->session->time_conv.time_zero; > - tc.time_cycles = jd->session->time_conv.time_cycles; > - tc.time_mask = jd->session->time_conv.time_mask; > - tc.cap_user_time_zero = jd->session->time_conv.cap_user_time_zero; > - tc.cap_user_time_short = jd->session->time_conv.cap_user_time_short; > + tc.time_shift = time_conv->time_shift; > + tc.time_mult = time_conv->time_mult; > + tc.time_zero = time_conv->time_zero; > > - if (!tc.cap_user_time_zero) > - return 0; > + /* > + * The event TIME_CONV was extended for the fields from "time_cycles" > + * when supported cap_user_time_short, for backward compatibility, > + * checks the event size and assigns these extended fields if these > + * fields are contained in the event. > + */ > + if (time_conv->header.size > > + ((void *)&time_conv->time_cycles - (void *)time_conv)) { > + tc.time_cycles = time_conv->time_cycles; > + tc.time_mask = time_conv->time_mask; > + tc.cap_user_time_zero = time_conv->cap_user_time_zero; > + tc.cap_user_time_short = time_conv->cap_user_time_short; > + > + if (!tc.cap_user_time_zero) > + return 0; > + } > > return tsc_to_perf_time(timestamp, &tc); > } >
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