On Fri, May 13, 2016 at 05:36:16PM -0600, Mathieu Poirier wrote:
> The following patch[1] adds a new "cpumode" to the perf_sample
> structure that gets initialised as events are read from the data
> event file.
>
> With the advent of HW tracers and more specifically the decoding of
> the traces they generate, function perf_session__deliver_synth_event()
> gets called directly from the infrastructure that decodes the traces,
> for example[2].
hum, but this one ends up calling perf_session__deliver_synth_event
with sample == NULL right?
I checked callers of perf_session__deliver_synth_event and it seems
all either init sample->cpumode or pass sample as NULL.. what do I miss?
thanks,
jirka
>
> As such initialisation of perf_sample::cpumode doesn't get done, which
> prevents the shared object name from being printed in the perf report
> output.
>
> Before this patch:
>
> 4.13% 4.13% uname [unknown] [H] 0x0000007fae8b4758
> 3.74% 3.74% uname [unknown] [H] 0x0000007fae8b4e50
> 2.06% 2.06% uname [unknown] [H] 0x0000007fae938af4
> 1.65% 1.65% uname [unknown] [H] 0x0000007fae938ae4
> 1.59% 1.59% uname [unknown] [H] 0x0000007fae98f7f4
> 1.50% 1.50% uname [unknown] [H] 0x0000007fae8b4e40
> 1.43% 1.43% uname [unknown] [H] 0x0000007fae938ac4
> 1.31% 1.31% uname [unknown] [H] 0x0000007fae86b0c0
> 1.26% 1.26% uname [unknown] [H] 0x0000007fae99b888
>
> And after this patch:
>
> 4.13% 4.13% uname libc-2.21.so [.] 0x0000000000078758
> 3.74% 3.74% uname libc-2.21.so [.] 0x0000000000078e50
> 2.06% 2.06% uname libc-2.21.so [.] 0x00000000000fcaf4
> 1.65% 1.65% uname libc-2.21.so [.] 0x00000000000fcae4
> 1.59% 1.59% uname ld-2.21.so [.] 0x000000000000a7f4
> 1.50% 1.50% uname libc-2.21.so [.] 0x0000000000078e40
> 1.43% 1.43% uname libc-2.21.so [.] 0x00000000000fcac4
> 1.31% 1.31% uname libc-2.21.so [.] 0x000000000002f0c0
> 1.26% 1.26% uname ld-2.21.so [.] 0x0000000000016888
>
> This was tested using CoreSight but the same is very likely to happen on
> IntelPT. I'm pretty sure this isn't the right solution but we can start
> building from that.
>
> Comments welcomed.
>
> [1]. commit 473398a21d28 ("perf tools: Add cpumode to struct perf_sample")
> [2]. http://lxr.free-electrons.com/source/tools/perf/util/intel-pt.c#L1806
>
> Signed-off-by: Mathieu Poirier <[email protected]>
> ---
> tools/perf/util/session.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
> index 4abd85c6346d..28cc405e7245 100644
> --- a/tools/perf/util/session.c
> +++ b/tools/perf/util/session.c
> @@ -1352,6 +1352,10 @@ int perf_session__deliver_synth_event(struct
> perf_session *session,
> {
> struct perf_evlist *evlist = session->evlist;
> struct perf_tool *tool = session->tool;
> + u8 mode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
> +
> + if (sample)
> + sample->cpumode = mode;
>
> events_stats__inc(&evlist->stats, event->header.type);
>
> --
> 2.5.0
>
