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Date:   Fri, 14 Jan 2022 11:51:38 -0300
From:   Arnaldo Carvalho de Melo <acme@kernel.org>
To:     Ian Rogers <irogers@google.com>
Cc:     Thomas Richter <tmricht@linux.ibm.com>,
        linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
        svens@linux.ibm.com, gor@linux.ibm.com, sumanthk@linux.ibm.com,
        hca@linux.ibm.com
Subject: Re: [PATCH] tools/perf: Fix perf test 7 Simple expression parser on
 s390
Message-ID: <YeGN+mT1yjJ60php@kernel.org>
References: <20211124090343.9436-1-tmricht@linux.ibm.com>
 <CAP-5=fXdOQUNDTXvt7GHRvu_7jyTPp_53f8_5DzDCXWCpWLtEQ@mail.gmail.com>
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Em Wed, Nov 24, 2021 at 07:41:40AM -0800, Ian Rogers escreveu:
> On Wed, Nov 24, 2021 at 1:04 AM Thomas Richter <tmricht@linux.ibm.com> wrote:
> >
> > Commit fdf1e29b6118 ("perf expr: Add metric literals for topology.")
> > fails on s390:
> >  # ./perf test -Fv 7
> >    ...
> >  # FAILED tests/expr.c:173 #num_dies >= #num_packages
> >    ---- end ----
> >    Simple expression parser: FAILED!
> >  #
> >
> > Investigating this issue leads to these functions:
> >  build_cpu_topology()
> >    +--> has_die_topology(void)
> >         {
> >            struct utsname uts;
> >
> >            if (uname(&uts) < 0)
> >                   return false;
> >            if (strncmp(uts.machine, "x86_64", 6))
> >                   return false;
> >            ....
> >         }
> >
> > which always returns false on s390. The caller build_cpu_topology()
> > checks has_die_topology() return value. On false the
> > the struct cpu_topology::die_cpu_list is not contructed and has zero
> > entries. This leads to the failing comparison: #num_dies >= #num_packages.
> > s390 of course has a positive number of packages.
> >
> > Fix this by adding s390 architecture to support CPU die list.

Thanks, applied.

- Arnaldo


> > Output after:
> >  # ./perf test -Fv 7
> >   7: Simple expression parser                                        :
> >   --- start ---
> >   division by zero
> >   syntax error
> >   ---- end ----
> >   Simple expression parser: Ok
> >  #
> > Cc: Ian Rogers <irogers@google.com>
> > Fixes: fdf1e29b6118 ("perf expr: Add metric literals for topology.")
> >
> > Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
> 
> Reviewed-by: Ian Rogers <irogers@google.com>
> 
> Thanks!
> Ian
> 
> > ---
> >  tools/perf/util/cputopo.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/tools/perf/util/cputopo.c b/tools/perf/util/cputopo.c
> > index 51b429c86f98..aad7a9e6e31b 100644
> > --- a/tools/perf/util/cputopo.c
> > +++ b/tools/perf/util/cputopo.c
> > @@ -165,7 +165,8 @@ static bool has_die_topology(void)
> >         if (uname(&uts) < 0)
> >                 return false;
> >
> > -       if (strncmp(uts.machine, "x86_64", 6))
> > +       if (strncmp(uts.machine, "x86_64", 6) &&
> > +           strncmp(uts.machine, "s390x", 5))
> >                 return false;
> >
> >         scnprintf(filename, MAXPATHLEN, DIE_CPUS_FMT,
> > --
> > 2.31.1
> >

-- 

- Arnaldo