Re: [External] : Re: RFC Re: [PATCH v2] perf jevents: Parse metrics during conversion

[Ian Rogers]

On Thu, Nov 17, 2022 at 10:16 AM John Garry <john.g.garry@xxxxxxxxxx> wrote:
>
> On 15/11/2022 17:35, John Garry wrote:
> > On 15/11/2022 17:26, Ian Rogers wrote:
> >> On Thu, Nov 10, 2022 at 10:48 AM Arnaldo Carvalho de Melo
> >> <acme@xxxxxxxxxx> wrote:
> >>>
> >>> Em Fri, Oct 28, 2022 at 10:57:02AM -0700, Ian Rogers escreveu:
> >>>> On Wed, Oct 12, 2022 at 9:42 AM Ian Rogers <irogers@xxxxxxxxxx> wrote:
> >>>>>
> >>>>> Currently the 'MetricExpr' json value is passed from the json
> >>>>> file to the pmu-events.c. This change introduces an expression
> >>>>> tree that is parsed into. The parsing is done largely by using
> >>>>> operator overloading and python's 'eval' function. Two advantages
> >>>>> in doing this are:
> >>>>>
> >>>>> 1) Broken metrics fail at compile time rather than relying on
> >>>>>     `perf test` to detect. `perf test` remains relevant for checking
> >>>>>     event encoding and actual metric use.
> >>>>>
> >>>>> 2) The conversion to a string from the tree can minimize the
> >>>>>     metric's string size, for example, preferring 1e6 over 1000000
> >>>>>     and removing unnecessary whitespace. On x86 this reduces the
> >>>>>     string size by 2,823bytes (0.06%).
> >>>>>
> >>>>> In future changes it would be possible to programmatically
> >>>>> generate the json expressions (a single line of text and so a
> >>>>> pain to write manually) for an architecture using the expression
> >>>>> tree. This could avoid copy-pasting metrics for all architecture
> >>>>> variants.
> >>>>>
> >>>>> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> >>>>
> >>>> Ping, PTAL.
> >>>
> >>> That would be really nice if people working with JSON, metrics, could
> >>> take a look at Ian's work and test it with their files, volunteers?
> >>
> >> Perhaps John could help?
> >
> > I'll have a look soon. I have to admit that I have not been tracking the
> > jevents changes as close as before.
>
> At least I can try to test it... so we support python 3.6 and later, right?
>
> I have 3.6 and acme perf/core generated pmu-events.c is ok for me, but
> this patch causes an error:
>
>    GEN     pmu-events/pmu-events.c
>   PERF_VERSION = 6.1.rc3.g39b7ecfa5b4a
>   GEN     perf-archive
>   GEN     perf-iostat
> Traceback (most recent call last):
>   File "pmu-events/jevents.py", line 7, in <module>
>     import metric
>   File "/home/john/kernel-dev2/tools/perf/pmu-events/metric.py", line
> 399, in <module>
>     class MetricGroup:
>   File "/home/john/kernel-dev2/tools/perf/pmu-events/metric.py", line
> 408, in MetricGroup
>     'MetricGroup']]):
> TypeError: 'type' object is not subscriptable
> make[3]: *** [pmu-events/Build:26: pmu-events/pmu-events.c] Error 1
> make[2]: *** [Makefile.perf:672: pmu-events/pmu-events-in.o] Error 2
> make[2]: *** Waiting for unfinished jobs....
>
>
> Any idea?

Apologies, this looks like a fault by me. I'll downgrade my python and
fix this for the next version.

Thanks!
Ian

> Thanks,
> John