On Wed, Mar 21, 2018 at 03:52:37PM -0300, Arnaldo Carvalho de Melo wrote: > Em Wed, Mar 21, 2018 at 05:04:46PM +0100, Jiri Olsa escreveu: > > On Wed, Mar 21, 2018 at 12:43:15PM -0300, Arnaldo Carvalho de Melo wrote: > > > Em Wed, Mar 21, 2018 at 12:40:35PM -0300, Arnaldo Carvalho de Melo > > > escreveu: > > > > 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... > > > > Well, how about we make it harder to build without key libraries? I.e. > > > if we detect that what we consider a core set of libraries isn't found > > > in the system, then we stop the build, warn about it and ask the user to > > > confirm that the build should proceed by passing some explicit > > > -DI_KNOW_WHAT_I_AM_DOING___PROCEED=doit > > > hum, not sure we want to complicate the build even more than it > > is now :-\ and IMO it still won't help much in Jin's problem, > > if user forces the build anyway > > Well, if a user _forces_ a build, not taking into consideration a > warning that _is_ emitted and _stops_ the build, about the functionality > it will lose by doing forcing the build, then comes back and complains > that that functionality is not present, then it becomes difficult to > help this user... :-) > > On the other hand, if the user forgets to install an important library, > the warning is emitted but the build proceeds, no explicit action was > performed, just a warning wasn't noticed, and the user complains, then > I'd say: "hey, are you sure library foo devel files were present when > you build it?", i.e. the support back and forth Jin is trying to avoid. > > And for users that _saw_ the warning, _knew_ they _didn't_ want that > functionality, to be reminded while running, say 'perf report' that > something they _decided not to have_ isn't present, then that could be > annoying, no? > > Lemme try another idea: what if we do something like gcc does and print > the features present when showing the version? > > I.e.: > > [acme@jouet perf]$ gcc -v > Using built-in specs. > COLLECT_GCC=/usr/bin/gcc > COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/7/lto-wrapper > OFFLOAD_TARGET_NAMES=nvptx-none > OFFLOAD_TARGET_DEFAULT=1 > Target: x86_64-redhat-linux > Configured with: ../configure --enable-bootstrap > --enable-languages=c,c++,objc,obj-c++,fortran,ada,go,lto --prefix=/usr > --mandir=/usr/share/man --infodir=/usr/share/info > --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared > --enable-threads=posix --enable-checking=release --enable-multilib > --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions > --enable-gnu-unique-object --enable-linker-build-id > --with-gcc-major-version-only --with-linker-hash-style=gnu --enable-plugin > --enable-initfini-array --with-isl --enable-libmpx > --enable-offload-targets=nvptx-none --without-cuda-driver > --enable-gnu-indirect-function --with-tune=generic --with-arch_32=i686 > --build=x86_64-redhat-linux > Thread model: posix > gcc version 7.3.1 20180303 (Red Hat 7.3.1-5) (GCC) > [acme@jouet perf]$ > > - Arnaldo
yep I guess you overlooked it in my previous reply ;-) jirka --- > 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
