Re: [PATCH v1 0/3] Support perf -vv

From: Jiri Olsa
Date: Mon Mar 26 2018 - 05:07:15 EST


On Mon, Mar 26, 2018 at 02:00:31AM -0700, Andi Kleen wrote:
> On Tue, Mar 27, 2018 at 12:07:01AM +0800, Jin Yao wrote:
> > We keep having bug reports that when users build perf on their own,
> > but they don't install some needed libraries such as libelf,
> > libbfd/libibery.
> >
> > The perf can build, but it is missing important functionality. And
> > users may complain that perf has issue or bug.
> >
> > This patch-set support 'perf -vv' which will print the compiled-in
> > status of libraries. Once users think perf missing some functionality,
> > it should be very easy for them to check the libraries status.
>
> I don't think this solves the problem. How should the user know
> that they need to run perf -vv. Also normal users don't know
> that libelf is needed for symbols for example.
>
> We need a warning that is visible together with the symbols
> and that clearly describes the problem.

IIRC we decided to go *with* the message in the perf report
or other affected command that would suggest to run 'perf -vv'
for more details

jirka

>
> -Andi
>
> >
> > For example:
> >
> > $ ./perf -vv
> > perf version 4.13.rc5.g9b7a81b
> > dwarf: [ on ]
> > dwarf_getlocations: [ on ]
> > glibc: [ on ]
> > gtk2: [ on ]
> > libaudit: [ off ]
> > 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 ]
> >
> > Jin Yao (3):
> > perf config: Add -DNO_GLIBC to CFLAGS
> > perf version: Print the status of compiled-in libraries
> > perf: Support perf -vv
> >
> > tools/perf/Makefile.config | 2 +
> > tools/perf/builtin-version.c | 125 +++++++++++++++++++++++++++++++++++++++++++
> > tools/perf/builtin.h | 1 +
> > tools/perf/perf.c | 6 +++
> > 4 files changed, 134 insertions(+)
> >
> > --
> > 2.7.4
> >