[perf top] annotation doesn't work, libunwind doesn't seem to be working either

[Ingo Molnar <mingo@kernel.org>]

BTW., here's a few other 'perf' annoyances I have, if anyone's 
listening :-)


1)

I cannot get the libunwind build-feature failure to go away:

...                               libcrypto: [ on  ]
...                               libunwind: [ OFF ]
...                             libcapstone: [ on  ]
...                               llvm-perf: [ on  ]

I do have libunwind-dev installed:

ii  libunwind-dev:amd64                                         1.6.2-3.1                                           amd64        library to determine the call-chain of a program - development
ii  libunwind8:amd64                                            1.6.2-3.1                                           amd64        library to determine the call-chain of a program - runtime

but it fails to link:

 kepler:~/tip/tools/build/feature> cat test-libunwind.make.output
 /usr/bin/ld: /tmp/cc2BfaNM.o: in function `main':
 test-libunwind.c:(.text+0x1c): undefined reference to `_Ux86_64_create_addr_space'
 /usr/bin/ld: test-libunwind.c:(.text+0x44): undefined reference to `_Ux86_64_init_remote'
 /usr/bin/ld: test-libunwind.c:(.text+0x6b): undefined reference to `_Ux86_64_dwarf_search_unwind_table'
 collect2: error: ld returned 1 exit status

I tried to install the libunwind-19-dev package, I tried to 
uninstall/reinstall - no combination seems to work.

perf is also totally unhelpful about resolving such issues - it used to 
issue tips about what packages to install, but those tips are not 
present anymore, for this one at least.

2)

More annoyingly, I cannot get source code annotation of the kernel to 
work - this might be related to the libunwind build failure (or not).

Within 'perf top' I go into a function, and I press 's', which is 
supposed to toggle the source code annotation ... but nothing happens.

'nothing happens' is perhaps the most passive-aggressive reaction a 
tool can give to a user. I'd prefer a *crash* to ignoring the keypress 
...

There's no error printed anywhere - just the color of the hexadecimal 
labels changes, nothing else.

'perf top' won't annotate kernel functions (despite me having a 
DEBUGINFO kernel package installed and booted), nor will it even 
annotate its own functions within 'perf', in a similar fashion.

It's similar for 'perf report' too, although that's not a surprise, 
they share much of the codebase.

'perf annotate --stdio' only shows an objdump --disassemble style 
output, but without any source annotations either.

This is a rather frustrating user experience. :-/

Thanks,

	Ingo