Magnus Karlsson b0abd1bc24 libbpf: remove likely/unlikely in xsk.h
This patch removes the use of likely and unlikely in xsk.h since they
create a dependency on Linux headers as reported by several
users. There have also been reports that the use of these decreases
performance as the compiler puts the code on two different cache lines
instead of on a single one. All in all, I think we are better off
without them.

Fixes: 1cad07884239 ("libbpf: add support for using AF_XDP sockets")
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-19 09:52:37 -07:00
2019-04-17 14:19:40 -07:00
2019-04-15 21:39:11 -07:00

This is a mirror of bpf-next linux tree
(https://kernel.googlesource.com/pub/scm/linux/kernel/git/bpf/bpf-next)
bpf-next/tools/lib/bpf directory plus its supporting header files.

The following files will by sync'ed with bpf-next repo:
  src/ <-> bpf-next/tools/lib/bpf/
  include/uapi/linux/bpf_common.h <-> bpf-next/tools/include/uapi/linux/bpf_common.h
  include/uapi/linux/bpf.h <-> bpf-next/tools/include/uapi/linux/bpf.h
  include/uapi/linux/btf.h <-> bpf-next/tools/include/uapi/linux/btf.h
  include/uapi/linux/if_link.h <-> bpf-next/tools/include/uapi/linux/if_link.h
  include/uapi/linux/if_xdp.h <-> bpf-next/tools/include/uapi/linux/if_xdp.h
  include/uapi/linux/netlink.h <-> bpf-next/tools/include/uapi/linux/netlink.h
  include/tools/libc_compat.h <-> bpf-next/tools/include/tools/libc_compat.h

Other header files at this repo (include/linux/*.h) are reduced versions of
their counterpart files at bpf-next/tools/include/linux/*.h to make compilation
successful.

Build
=====
libelf is an internal dependency of libbpf and thus it is required to link
against and must be installed on the system for applications to work.
pkg-config is used by default to find libelf, and the program called can be
overridden with PKG_CONFIG.
If using pkg-config at build time is not desired, it can be disabled by setting
NO_PKG_CONFIG=1 when calling make.

To build both static libbpf.a and shared libbpf.so:
  cd src
  make

To build only static libbpf.a library in directory
build/ and install them together with libbpf headers in a staging directory
root/:
  cd src
  mkdir build root
  BUILD_STATIC_ONLY=y OBJDIR=build DESTDIR=root make install

To build both static libbpf.a and shared libbpf.so against a custom libelf
dependency installed in /build/root/ and install them together with libbpf
headers in a build directory /build/root/:

  cd src
  PKG_CONFIG_PATH=/build/root/lib64/pkgconfig DESTDIR=/build/root make install

To integrate libbpf into a project which uses Meson building system define
[wrap-git] file in `subprojects` folder.
To add libbpf dependency to the parent parent project, e.g. for
libbpf_static_dep:

   libbpf_obj = subproject('libbpf', required : true)
   libbpf_static_dep = libbpf_proj.get_variable('libbpf_static_dep')

To validate changes to meson.build

   python3 meson.py build
   ninja -C build/

To install headers, libs and pkgconfig
   cd build
   ninja install
Description
Automated upstream mirror for libbpf stand-alone build.
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