1. 22 11月, 2018 1 次提交
    • A
      tools build feature: Check if eventfd() is available · 11c6cbe7
      Arnaldo Carvalho de Melo 提交于
      A new 'perf bench epoll' will use this, and to disable it for older
      systems, add a feature test for this API.
      
      This is just a simple program that if successfully compiled, means that
      the feature is present, at least at the library level, in a build that
      sets the output directory to /tmp/build/perf (using O=/tmp/build/perf),
      we end up with:
      
        $ ls -la /tmp/build/perf/feature/test-eventfd*
        -rwxrwxr-x. 1 acme acme 8176 Nov 21 15:58 /tmp/build/perf/feature/test-eventfd.bin
        -rw-rw-r--. 1 acme acme  588 Nov 21 15:58 /tmp/build/perf/feature/test-eventfd.d
        -rw-rw-r--. 1 acme acme    0 Nov 21 15:58 /tmp/build/perf/feature/test-eventfd.make.output
        $ ldd /tmp/build/perf/feature/test-eventfd.bin
      	  linux-vdso.so.1 (0x00007fff3bf3f000)
      	  libc.so.6 => /lib64/libc.so.6 (0x00007fa984061000)
      	  /lib64/ld-linux-x86-64.so.2 (0x00007fa984417000)
        $ grep eventfd -A 2 -B 2 /tmp/build/perf/FEATURE-DUMP
        feature-dwarf=1
        feature-dwarf_getlocations=1
        feature-eventfd=1
        feature-fortify-source=1
        feature-sync-compare-and-swap=1
        $
      
      The main thing here is that in the end we'll have -DHAVE_EVENTFD in
      CFLAGS, and then the 'perf bench' entry needing that API can be
      selectively pruned.
      
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Davidlohr Bueso <dbueso@suse.de>
      Cc: Jason Baron <jbaron@akamai.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Wang Nan <wangnan0@huawei.com>
      Link: https://lkml.kernel.org/n/tip-wkeldwob7dpx6jvtuzl8164k@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      11c6cbe7
  2. 20 11月, 2018 1 次提交
  3. 12 7月, 2018 1 次提交
  4. 08 3月, 2018 2 次提交
  5. 25 1月, 2018 1 次提交
  6. 17 1月, 2018 1 次提交
    • J
      tools: bpftool: add -DPACKAGE when including bfd.h · 39b72ccd
      Jiong Wang 提交于
      bfd.h is requiring including of config.h except when PACKAGE or
      PACKAGE_VERSION are defined.
      
        /* PR 14072: Ensure that config.h is included first.  */
        #if !defined PACKAGE && !defined PACKAGE_VERSION
        #error config.h must be included before this header
        #endif
      
      This check has been introduced since May-2012. It doesn't show up in bfd.h
      on some Linux distribution, probably because distributions have remove it
      when building the package.
      
      However, sometimes the user might just build libfd from source code then
      link bpftool against it. For this case, bfd.h will be original that we need
      to define PACKAGE or PACKAGE_VERSION.
      Acked-by: NJakub Kicinski <jakub.kicinski@netronome.com>
      Signed-off-by: NJiong Wang <jiong.wang@netronome.com>
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      39b72ccd
  7. 30 12月, 2017 1 次提交
  8. 05 12月, 2017 1 次提交
  9. 02 11月, 2017 1 次提交
    • G
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman 提交于
      Many source files in the tree are missing licensing information, which
      makes it harder for compliance tools to determine the correct license.
      
      By default all files without license information are under the default
      license of the kernel, which is GPL version 2.
      
      Update the files which contain no license information with the 'GPL-2.0'
      SPDX license identifier.  The SPDX identifier is a legally binding
      shorthand, which can be used instead of the full boiler plate text.
      
      This patch is based on work done by Thomas Gleixner and Kate Stewart and
      Philippe Ombredanne.
      
      How this work was done:
      
      Patches were generated and checked against linux-4.14-rc6 for a subset of
      the use cases:
       - file had no licensing information it it.
       - file was a */uapi/* one with no licensing information in it,
       - file was a */uapi/* one with existing licensing information,
      
      Further patches will be generated in subsequent months to fix up cases
      where non-standard license headers were used, and references to license
      had to be inferred by heuristics based on keywords.
      
      The analysis to determine which SPDX License Identifier to be applied to
      a file was done in a spreadsheet of side by side results from of the
      output of two independent scanners (ScanCode & Windriver) producing SPDX
      tag:value files created by Philippe Ombredanne.  Philippe prepared the
      base worksheet, and did an initial spot review of a few 1000 files.
      
      The 4.13 kernel was the starting point of the analysis with 60,537 files
      assessed.  Kate Stewart did a file by file comparison of the scanner
      results in the spreadsheet to determine which SPDX license identifier(s)
      to be applied to the file. She confirmed any determination that was not
      immediately clear with lawyers working with the Linux Foundation.
      
      Criteria used to select files for SPDX license identifier tagging was:
       - Files considered eligible had to be source code files.
       - Make and config files were included as candidates if they contained >5
         lines of source
       - File already had some variant of a license header in it (even if <5
         lines).
      
      All documentation files were explicitly excluded.
      
      The following heuristics were used to determine which SPDX license
      identifiers to apply.
      
       - when both scanners couldn't find any license traces, file was
         considered to have no license information in it, and the top level
         COPYING file license applied.
      
         For non */uapi/* files that summary was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0                                              11139
      
         and resulted in the first patch in this series.
      
         If that file was a */uapi/* path one, it was "GPL-2.0 WITH
         Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0 WITH Linux-syscall-note                        930
      
         and resulted in the second patch in this series.
      
       - if a file had some form of licensing information in it, and was one
         of the */uapi/* ones, it was denoted with the Linux-syscall-note if
         any GPL family license was found in the file or had no licensing in
         it (per prior point).  Results summary:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|------
         GPL-2.0 WITH Linux-syscall-note                       270
         GPL-2.0+ WITH Linux-syscall-note                      169
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
         LGPL-2.1+ WITH Linux-syscall-note                      15
         GPL-1.0+ WITH Linux-syscall-note                       14
         ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
         LGPL-2.0+ WITH Linux-syscall-note                       4
         LGPL-2.1 WITH Linux-syscall-note                        3
         ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
         ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1
      
         and that resulted in the third patch in this series.
      
       - when the two scanners agreed on the detected license(s), that became
         the concluded license(s).
      
       - when there was disagreement between the two scanners (one detected a
         license but the other didn't, or they both detected different
         licenses) a manual inspection of the file occurred.
      
       - In most cases a manual inspection of the information in the file
         resulted in a clear resolution of the license that should apply (and
         which scanner probably needed to revisit its heuristics).
      
       - When it was not immediately clear, the license identifier was
         confirmed with lawyers working with the Linux Foundation.
      
       - If there was any question as to the appropriate license identifier,
         the file was flagged for further research and to be revisited later
         in time.
      
      In total, over 70 hours of logged manual review was done on the
      spreadsheet to determine the SPDX license identifiers to apply to the
      source files by Kate, Philippe, Thomas and, in some cases, confirmation
      by lawyers working with the Linux Foundation.
      
      Kate also obtained a third independent scan of the 4.13 code base from
      FOSSology, and compared selected files where the other two scanners
      disagreed against that SPDX file, to see if there was new insights.  The
      Windriver scanner is based on an older version of FOSSology in part, so
      they are related.
      
      Thomas did random spot checks in about 500 files from the spreadsheets
      for the uapi headers and agreed with SPDX license identifier in the
      files he inspected. For the non-uapi files Thomas did random spot checks
      in about 15000 files.
      
      In initial set of patches against 4.14-rc6, 3 files were found to have
      copy/paste license identifier errors, and have been fixed to reflect the
      correct identifier.
      
      Additionally Philippe spent 10 hours this week doing a detailed manual
      inspection and review of the 12,461 patched files from the initial patch
      version early this week with:
       - a full scancode scan run, collecting the matched texts, detected
         license ids and scores
       - reviewing anything where there was a license detected (about 500+
         files) to ensure that the applied SPDX license was correct
       - reviewing anything where there was no detection but the patch license
         was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
         SPDX license was correct
      
      This produced a worksheet with 20 files needing minor correction.  This
      worksheet was then exported into 3 different .csv files for the
      different types of files to be modified.
      
      These .csv files were then reviewed by Greg.  Thomas wrote a script to
      parse the csv files and add the proper SPDX tag to the file, in the
      format that the file expected.  This script was further refined by Greg
      based on the output to detect more types of files automatically and to
      distinguish between header and source .c files (which need different
      comment types.)  Finally Greg ran the script using the .csv files to
      generate the patches.
      Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  10. 19 7月, 2017 1 次提交
  11. 13 4月, 2017 1 次提交
  12. 12 4月, 2017 1 次提交
  13. 04 3月, 2017 2 次提交
  14. 07 12月, 2016 1 次提交
    • W
      perf build: Check LLVM version in feature check · a940cad3
      Wang Nan 提交于
      Cancel builtin llvm and clang support when LLVM version is less than
      3.9.0: following commits uses newer API.
      
      Since Clang/LLVM's API is not guaranteed to be stable, add a
      test-llvm-version.cpp feature checker, issue warning if LLVM found in
      compiling environment is not tested yet.
      
      Committer Notes:
      
      Testing it:
      
      Environment:
      
        $ cat /etc/fedora-release
        Fedora release 25 (Twenty Five)
        $ rpm -q llvm-devel clang-devel
        llvm-devel-3.8.0-1.fc25.x86_64
        clang-devel-3.8.0-2.fc25.x86_64
        $
      
      Before:
      
        $  make -k LIBCLANGLLVM=1 O=/tmp/build/perf -C tools/perf install-bin
        make: Entering directory '/home/acme/git/linux/tools/perf'
          BUILD:   Doing 'make -j4' parallel build
        Warning: tools/include/uapi/linux/bpf.h differs from kernel
        Warning: tools/arch/arm/include/uapi/asm/kvm.h differs from kernel
          INSTALL  GTK UI
          LINK     /tmp/build/perf/perf
        /tmp/build/perf/libperf.a(libperf-in.o): In function `perf::createCompilerInvocation(llvm::SmallVector<char const*, 16u>, llvm::StringRef&, clang::DiagnosticsEngine&)':
        /home/acme/git/linux/tools/perf/util/c++/clang.cpp:56: undefined reference to `clang::tooling::newInvocation(clang::DiagnosticsEngine*, llvm::SmallVector<char const*, 16u> const&)'
        /tmp/build/perf/libperf.a(libperf-in.o): In function `perf::getModuleFromSource(llvm::SmallVector<char const*, 16u>, llvm::StringRef, llvm::IntrusiveRefCntPtr<clang::vfs::FileSystem>)':
        /home/acme/git/linux/tools/perf/util/c++/clang.cpp:68: undefined reference to `clang::CompilerInstance::CompilerInstance(std::shared_ptr<clang::PCHContainerOperations>, bool)'
        /home/acme/git/linux/tools/perf/util/c++/clang.cpp:69: undefined reference to `clang::CompilerInstance::createDiagnostics(clang::DiagnosticConsumer*, bool)'
        <SNIP>
      
      After:
      
        Makefile.config:807: No suitable libLLVM found, disabling builtin clang and llvm support. Please install llvm-dev(el) (>= 3.9.0)
      
      Updating the environment to a locally built LLVM 4.0 + clang 3.9 (forgot
      to git pull, duh) combo, all works as expected, it is properly detected
      and built into the resulting perf binary.
      Signed-off-by: NWang Nan <wangnan0@huawei.com>
      Reported-and-Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Alexei Starovoitov <ast@fb.com>
      Cc: He Kuang <hekuang@huawei.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Joe Stringer <joe@ovn.org>
      Cc: Zefan Li <lizefan@huawei.com>
      Cc: pi3orama@163.com
      Link: http://lkml.kernel.org/r/20161206072230.7651-1-wangnan0@huawei.com
      [ Change the warning message a bit (add 'suitable' and 'builtin'), clarifying it, see committer notes above ]
      Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      a940cad3
  15. 06 12月, 2016 3 次提交
  16. 14 11月, 2016 1 次提交
  17. 06 10月, 2016 1 次提交
  18. 14 7月, 2016 1 次提交
  19. 13 7月, 2016 1 次提交
    • A
      perf tools: Add feature detection for gelf_getnote() · 1c1a3a47
      Arnaldo Carvalho de Melo 提交于
      That is not present on some libelf implementations, such as the one used
      in Alpine Linux: libelf-0.8.13.
      
      This ends up disabling the SDT code, that relies on this function.
      
      One alternative would be to provide an weak fallback implementation or
      the open coded variant used by the buildid sysfs notes reading code.
      
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
      Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Masami Hiramatsu <mhiramat@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Wang Nan <wangnan0@huawei.com>
      Link: http://lkml.kernel.org/n/tip-82lh22ybedy9b9lych8xj12g@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      1c1a3a47
  20. 05 7月, 2016 1 次提交
  21. 12 5月, 2016 1 次提交
  22. 11 5月, 2016 2 次提交
  23. 06 4月, 2016 1 次提交
  24. 05 2月, 2016 1 次提交
  25. 17 12月, 2015 1 次提交
  26. 30 10月, 2015 1 次提交
    • R
      tools build: Fix libiberty feature detection · 3af6ed84
      Rabin Vincent 提交于
      Any CFLAGS or LDFLAGS set by the user need to be passed to the feature
      build command.  This many include for example -I or -L to point to
      libraries and include files in custom paths.
      
      In most of the test-*.bin rules in build/feature/Makefile, we use the BUILD
      macro which always sends in CFLAGS and LDFLAGS.  The libiberty build line
      however doesn't use the BUILD macro and thus needs to send in CFLAGS and
      LDFLAGS explicitly.  Without this, when using custom CFLAGS/LDFLAGS, libiberty
      fails to be detected and the perf link fails with something like:
      
         LINK     perf
        libbfd.a(bfd.o): In function `bfd_errmsg':
        bfd.c:(.text+0x168): undefined reference to `xstrerror'
        bbfd.a(opncls.o): In function `_bfd_new_bfd':
        opncls.c:(.text+0xe8): undefined reference to `objalloc_create'
        ...
      Signed-off-by: NRabin Vincent <rabin.vincent@axis.com>
      Acked-by: NJiri Olsa <jolsa@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Rabin Vincent <rabinv@axis.com>
      Link: http://lkml.kernel.org/r/1446104978-26429-2-git-send-email-rabin.vincent@axis.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      3af6ed84
  27. 18 9月, 2015 2 次提交
    • A
      tools build: Add test for presence of __get_cpuid() gcc builtin · b0063dbf
      Arnaldo Carvalho de Melo 提交于
      The auxtrace code needed by Intel PT uses the __get_cpuid() gcc builtin,
      that is not present in old systems, breaking the build.
      
      Add a test to check for that builtin and disable AUXTRACE in those
      systems.
      
        [acme@rhel5 linux]$  make NO_LIBPERL=1 -C tools/perf O=/tmp/build/perf install-bin
        make: Entering directory `/home/acme/git/linux/tools/perf'
          BUILD:   Doing 'make -j2' parallel build
      
        Auto-detecting system features:
        <SNIP>
        ...                          lzma: [ on  ]
        ...                     get_cpuid: [ OFF ]
        <SNIP>
        config/Makefile:630: Your gcc lacks the __get_cpuid() builtin, disables support for auxtrace/Intel PT, please install a newer gcc
          MKDIR    /tmp/build/perf/util/
        <SNIP>
      
      This fixes the build on old systems such as RHEL/CentOS 5.11.
      
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Victor Kamensky <victor.kamensky@linaro.org>
      Cc: Vinson Lee <vlee@twopensource.com>
      Cc: Wang Nan <wangnan0@huawei.com>
      Link: http://lkml.kernel.org/n/tip-d4puslul0jltoodzpx9r4sje@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      b0063dbf
    • A
      tools build: Add test for presence of numa_num_possible_cpus() in libnuma · f8ac8606
      Arnaldo Carvalho de Melo 提交于
      The existing numa test checks only if numa.h and numa_available() are
      present, but that can be satisfied with an old libnuma that is not
      enough for the 'perf bench numa' entry, so add a test to check for that:
      
        [acme@rhel5 linux]$  make NO_AUXTRACE=1 NO_LIBPERL=1 -C tools/perf O=/tmp/build/perf install-bin
        make: Entering directory `/home/acme/git/linux/tools/perf'
          BUILD:   Doing 'make -j2' parallel build
      
        Auto-detecting system features:
        ...                        libelf: [ on  ]
        ...                       libnuma: [ on  ]
        ...        numa_num_possible_cpus: [ OFF ]
        ...                       libperl: [ on  ]
      
        <SNIP>
        config/Makefile:577: Old numa library found, disables 'perf bench numa mem' benchmark, please install numactl-devel/libnuma-devel/libnuma-dev >= 2.0.8
          INSTALL  binaries
        <SNIP>
      
      This fixes the build on old systems such as RHEL/CentOS 5.11.
      
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Victor Kamensky <victor.kamensky@linaro.org>
      Cc: Vinson Lee <vlee@twopensource.com>
      Cc: Wang Nan <wangnan0@huawei.com>
      Link: http://lkml.kernel.org/n/tip-zqriqkezppi2de2iyjin1tnc@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      f8ac8606
  28. 14 8月, 2015 1 次提交
  29. 07 8月, 2015 1 次提交
    • W
      bpf tools: Introduce 'bpf' library and add bpf feature check · 1b76c13e
      Wang Nan 提交于
      This is the first patch of libbpf. The goal of libbpf is to create a
      standard way for accessing eBPF object files. This patch creates
      'Makefile' and 'Build' for it, allows 'make' to build libbpf.a and
      libbpf.so, 'make install' to put them into proper directories.
      Most part of Makefile is borrowed from traceevent.
      
      Before building, it checks the existence of libelf in Makefile, and deny
      to build if not found. Instead of throwing an error if libelf not found,
      the error raises in a phony target "elfdep". This design is to ensure
      'make clean' still workable even if libelf is not found.
      
      Because libbpf requires 'kern_version' field set for 'union bpf_attr'
      (bpfdep" is used for that dependency), Kernel BPF API is also checked
      by intruducing a new feature check 'bpf' into tools/build/feature,
      which checks the existence and version of linux/bpf.h. When building
      libbpf, it searches that file from include/uapi/linux in kernel source
      tree (controlled by FEATURE_CHECK_CFLAGS-bpf). Since it searches kernel
      source tree it reside, installing of newest kernel headers is not
      required, except we are trying to port these files to an old kernel.
      
      To avoid checking that file when perf building, the newly introduced
      'bpf' feature check doesn't added into FEATURE_TESTS and
      FEATURE_DISPLAY by default in tools/build/Makefile.feature, but added
      into libbpf's specific.
      Signed-off-by: NWang Nan <wangnan0@huawei.com>
      Acked-by: NAlexei Starovoitov <ast@plumgrid.com>
      Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
      Cc: Daniel Borkmann <daniel@iogearbox.net>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: He Kuang <hekuang@huawei.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Kaixu Xia <xiakaixu@huawei.com>
      Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Zefan Li <lizefan@huawei.com>
      Bcc: pi3orama@163.com
      Link: http://lkml.kernel.org/r/1435716878-189507-4-git-send-email-wangnan0@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      1b76c13e
  30. 22 3月, 2015 2 次提交
  31. 19 3月, 2015 2 次提交
  32. 02 3月, 2015 1 次提交
    • I
      perf tools: Improve feature test debuggability · b49f1a4b
      Ingo Molnar 提交于
      Certain feature tests fail with link errors:
      
        triton:~/tip/tools/perf/config/feature-checks> make test-libbabeltrace.bin
        gcc -MD  -o test-libbabeltrace.bin test-libbabeltrace.c # -lbabeltrace provided by
        /tmp/cc6dRSqd.o: In function `main':
        test-libbabeltrace.c:(.text+0xf): undefined reference to `bt_ctf_stream_class_get_packet_context_type'
      
      although they should already fail with a build error due to lack of a
      proper prototype for the function. Due to this I first tried to find
      which library was missing - while it was the whole feature that was
      missing from the .h file already.
      
      To solve this, propagate -Wall -Werror to all testcases and remove them
      from testcase Makefile rules that used them explicitly.
      
      A missing feature now outputs:
      
        triton:~/tip/tools/perf/config/feature-checks> make test-libbabeltrace.bin
        gcc -MD  -Wall -Werror -o test-libbabeltrace.bin test-libbabeltrace.c  # -lbabeltrace provided by
        test-libbabeltrace.c: In function ‘main’:
        test-libbabeltrace.c:6:2: error: implicit declaration of function ‘bt_ctf_stream_class_get_packet_context_type’ [-Werror=implicit-function-declaration]
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      Cc: David Ahern <david.ahern@oracle.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/20150228091627.GF31887@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      b49f1a4b