Re: [PATCH] perf stat: Fix duration_time value for higher intervals

From: Jiri Olsa <jolsa@redhat.com>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>,
	Joakim Zhang <qiangqing.zhang@nxp.com>,
	Andi Kleen <ak@linux.intel.com>,
	lkml <linux-kernel@vger.kernel.org>,
	Ingo Molnar <mingo@kernel.org>,
	Namhyung Kim <namhyung@kernel.org>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Michael Petlan <mpetlan@redhat.com>
Subject: Re: [PATCH] perf stat: Fix duration_time value for higher intervals
Date: Mon, 18 May 2020 17:48:48 +0200	[thread overview]
Message-ID: <20200518154848.GA11620@krava> (raw)
In-Reply-To: <20200518152351.GD24211@kernel.org>

On Mon, May 18, 2020 at 12:23:51PM -0300, Arnaldo Carvalho de Melo wrote:
> Em Mon, May 18, 2020 at 03:14:45PM +0200, Jiri Olsa escreveu:
> > Joakim reported wrong duration_time value for interval bigger
> > than 4000 [1].
> > 
> > The problem is in the interval value we pass to update_stats
> > function, which is typed as 'unsigned int' and overflows when
> > we get over 2^32 (happens between intervals 4000 and 5000).
> > 
> > Retyping the passed value to unsigned long long.
> 
> Thanks, applied and added this:
> 
> Fixes: b90f1333ef08 ("perf stat: Update walltime_nsecs_stats in interval mode")
> 
> Ok?

yep, thanks
jirka

> 
> - Arnaldo
> 
> > [1] https://www.spinics.net/lists/linux-perf-users/msg11777.html
> > 
> > Reported-by: Joakim Zhang <qiangqing.zhang@nxp.com>
> > Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> > ---
> >  tools/perf/builtin-stat.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> > index e0c1ad23c768..4deb2d46a343 100644
> > --- a/tools/perf/builtin-stat.c
> > +++ b/tools/perf/builtin-stat.c
> > @@ -367,7 +367,7 @@ static void process_interval(void)
> >  	}
> >  
> >  	init_stats(&walltime_nsecs_stats);
> > -	update_stats(&walltime_nsecs_stats, stat_config.interval * 1000000);
> > +	update_stats(&walltime_nsecs_stats, stat_config.interval * 1000000ULL);
> >  	print_counters(&rs, 0, NULL);
> >  }
> >  
> > -- 
> > 2.25.4
> > 
> 
> -- 
> 
> - Arnaldo
>