linux-kernel - Re: [PATCH v1 2/2] perf metricgroup: Don't early exit if no CPUID table exists

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20260206123310.GF3529712@e132581.arm.com>
Date: Fri, 6 Feb 2026 12:33:10 +0000
From: Leo Yan <leo.yan@....com>
To: Ian Rogers <irogers@...gle.com>
Cc: Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>,
	Arnaldo Carvalho de Melo <acme@...nel.org>,
	Namhyung Kim <namhyung@...nel.org>,
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
	Jiri Olsa <jolsa@...nel.org>,
	Adrian Hunter <adrian.hunter@...el.com>,
	James Clark <james.clark@...aro.org>,
	linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1 2/2] perf metricgroup: Don't early exit if no CPUID
 table exists

On Fri, Feb 06, 2026 at 10:45:43AM +0000, Leo Yan wrote:
> On Thu, Feb 05, 2026 at 10:36:03AM -0800, Ian Rogers wrote:
> > The failure to find a table of metrics with a CPUID shouldn't early
> > exit as the metric code will now also consider the default table.
> > When searching for a metric or metric group,
> > pmu_metrics_table__for_each_metric considers all tables and so the
> > caller doesn't need to switch the table to do this.
> > 
> > Fixes: c7adeb0974f1 ("perf jevents: Add set of common metrics based on default ones")
> > Signed-off-by: Ian Rogers <irogers@...gle.com>
> > ---
> >  tools/perf/util/metricgroup.c | 18 +++++-------------
> >  1 file changed, 5 insertions(+), 13 deletions(-)
> > 
> > diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
> > index 40a1e14de418..46bf4dfeebc8 100644
> > --- a/tools/perf/util/metricgroup.c
> > +++ b/tools/perf/util/metricgroup.c
> > @@ -1562,8 +1562,6 @@ int metricgroup__parse_groups(struct evlist *perf_evlist,
> >  {
> >  	const struct pmu_metrics_table *table = pmu_metrics_table__find();
> >  
> > -	if (!table)
> > -		return -EINVAL;
> >  	if (hardware_aware_grouping)
> >  		pr_debug("Use hardware aware grouping instead of traditional metric grouping method\n");
> >  
> > @@ -1601,22 +1599,16 @@ static int metricgroup__has_metric_or_groups_callback(const struct pmu_metric *p
> >  
> >  bool metricgroup__has_metric_or_groups(const char *pmu, const char *metric_or_groups)
> >  {
> > -	const struct pmu_metrics_table *tables[2] = {
> > -		pmu_metrics_table__find(),
> > -		pmu_metrics_table__default(),
> > -	};
> > +	const struct pmu_metrics_table *table = pmu_metrics_table__find();
> 
> Here should be:
> 
>   const struct pmu_metrics_table *table = pmu_metrics_table__default();

Or, I think you should not change metricgroup__has_metric_or_groups().
The change only in metricgroup__parse_groups() can fix my issue.

Thanks,
Leo