Messages in this thread | | | Subject | Re: [PATCH] perf util: Display warning when perf report/annotate is missing some libs | From | "Jin, Yao" <> | Date | Thu, 22 Mar 2018 09:04:10 +0800 |
| |
On 3/21/2018 11:38 PM, Jiri Olsa wrote: > 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? > >>> 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 >
I'm just afraid that the newbie will not check the -vv on his own when he gets trouble in using perf.
In other words, if a user is experienced and he knows -vv yet, I may assume that he should know installing all libraries before building the perf.
This patch is specific for the perf newbie. It will directly shows the error/warning when the user launches the perf binary. It will have a little bit helps, I guess. :)
Thanks Jin Yao
| |