Re: [PATCH v3 14/15] perf jevents: Add support for metricgroup descriptions

From: Arnaldo Carvalho de Melo
Date: Tue May 23 2023 - 15:18:32 EST


Em Tue, May 23, 2023 at 08:58:25AM -0700, Ian Rogers escreveu:
> On Tue, May 23, 2023 at 8:16 AM Arnaldo Carvalho de Melo
> <acme@xxxxxxxxxx> wrote:
> >
> > Em Wed, May 17, 2023 at 10:38:03AM -0700, Ian Rogers escreveu:
> > > Metrics have a field where the groups they belong to are listed like
> > > the following from
> > > tools/perf/pmu-events/arch/x86/skylakex/skx-metrics.json:
> > >
> > > "MetricGroup": "PGO;TmaL1;TopdownL1;tma_L1_group",
> > > "MetricName": "tma_frontend_bound",
> >
> > LD /tmp/build/perf-tools-next/util/perf-in.o
> > LD /tmp/build/perf-tools-next/perf-in.o
> > CC /tmp/build/perf-tools-next/pmu-events/pmu-events.o
> > In file included from /var/home/acme/git/perf-tools-next/tools/include/linux/bitmap.h:9,
> > from /var/home/acme/git/perf-tools-next/tools/perf/util/header.h:10,
> > from /tmp/build/perf-tools-next/pmu-events/pmu-events.c:3:
> > /tmp/build/perf-tools-next/pmu-events/pmu-events.c: In function ‘describe_metricgroup’:
> > /var/home/acme/git/perf-tools-next/tools/include/linux/kernel.h:102:25: error: overflow in conversion from ‘long unsigned int’ to ‘int’ changes value from ‘18446744073709551615’ to ‘-1’ [-Werror=overflow]
> > 102 | #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
> > | ^
> > /tmp/build/perf-tools-next/pmu-events/pmu-events.c:61603:29: note: in expansion of macro ‘ARRAY_SIZE’
> > 61603 | int low = 0, high = ARRAY_SIZE(metricgroups) - 1;
> > | ^~~~~~~~~~
> > cc1: all warnings being treated as errors
> > make[3]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:98: /tmp/build/perf-tools-next/pmu-events/pmu-events.o] Error 1
> > make[2]: *** [Makefile.perf:679: /tmp/build/perf-tools-next/pmu-events/pmu-events-in.o] Error 2
> > make[1]: *** [Makefile.perf:236: sub-make] Error 2
> > make: *** [Makefile:113: install-bin] Error 2
> > make: Leaving directory '/var/home/acme/git/perf-tools-next/tools/perf'
> >
> > Performance counter stats for 'make -k BUILD_BPF_SKEL=1 CORESIGHT=1 O=/tmp/build/perf-tools-next -C tools/perf install-bin':
> >
> > 241752971879 cycles:u
> > 296060193784 instructions:u # 1.22 insn per cycle
> >
> > 6.129451072 seconds time elapsed
> >
> > 59.018259000 seconds user
> > 12.132871000 seconds sys
> >
> >
> > ⬢[acme@toolbox perf-tools-next]$ fg
> > git rebase -i HEAD~15
> >
> > [1]+ Stopped git rebase -i HEAD~15
> > ⬢[acme@toolbox perf-tools-next]$ git log --oneline -1
> > 995a2beaa64deb7b (HEAD) perf jevents: Add support for metricgroup descriptions
> > ⬢[acme@toolbox perf-tools-next]$
> >
> > Applied 1-13, pushing to tmp.perf-tools-next,
> >
> > - Arnaldo
>
> Thanks, there's a missing (int) cast on ARRAY_SIZE. It doesn't make
> sense to resend the entire series so I'll wait to rebase, add the cast
> and then resend in v2 - that's unless you beat me to it ;-)

I made the amendment below, now lets see why it is not building after
the next patch is applied...

- Arnaldo

diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-events/jevents.py
index 8fca7c9adee0c354..7ed258be18292241 100755
--- a/tools/perf/pmu-events/jevents.py
+++ b/tools/perf/pmu-events/jevents.py
@@ -938,7 +938,7 @@ static const int metricgroups[][2] = {

const char *describe_metricgroup(const char *group)
{
- int low = 0, high = ARRAY_SIZE(metricgroups) - 1;
+ int low = 0, high = (int)ARRAY_SIZE(metricgroups) - 1;

while (low <= high) {
int mid = (low + high) / 2;