Re: [PATCH] perf util: Display warning when perf report/annotate is missing some libs

Arnaldo Carvalho de Melo
2018-03-21T15:40:44Z

Em Wed, Mar 21, 2018 at 04:38:07PM +0100, Jiri Olsa escreveu:
> On Wed, Mar 21, 2018 at 10:11:10AM +0800, Jin, Yao wrote:
> > Hi Jiri,
> >
> > I'm still thinking it's worth displaying the warning when perf missing some
> > libraries.
> >
> > Somebody just told me that perf didn't work well. While after some
> > investigations, I found it's just missing some libraries when building the
> > perf.
> >
> > But I have spent some time on getting the root cause. If with this patch, it
> > should be very easily to know that.
>
> true.. Arnaldo, any feedback on this one?

Lemme re-read the thread...

> > > I just think it'd better provide some hints to user. For example,
> > > "symbol is disabled and you need to install libelf/xxx", say something
> > > like that.
> > >
> > > But it looks the column can't contain too much information (i.e. no more
> > > space to contain the entire hints).
> > >
> > > Any idea? Or just add this warning in verbose mode?
> > >
> > > > also your change does not affect tui mode
> > > >
> > > > annotation for some reason does not start at all.. could be
> > > > little more verbose ;-)
> > > >
> > > > jirka
> > > >
> > >
> > > Yes, it doesn't affect tui mode.
> > >
> > > Or we just add this warning in verbose mode?
> > >
> > > e.g. perf report -v?
>
> how about displaying libraries separately with -vv output,
> that would mimic the build message, like:
>
> $ ./perf -vv
> perf version 4.16.rc6.g18fd48
>
> dwarf: [ on ]
> dwarf_getlocations: [ on ]
> glibc: [ on ]
> gtk2: [ on ]
> libaudit: [ on ]
> libbfd: [ on ]
> libelf: [ on ]
> libnuma: [ on ]
> numa_num_possible_cpus: [ on ]
> libperl: [ on ]
> libpython: [ on ]
> libslang: [ on ]
> libcrypto: [ on ]
> libunwind: [ on ]
> libdw-dwarf-unwind: [ on ]
> zlib: [ on ]
> lzma: [ on ]
> get_cpuid: [ on ]
> bpf: [ on ]
>
> and perf -vvv could display the 'make VF=1' info
>
> jirka