This patch set adds ability to memory-map BPF array maps (single- and multi-element). The primary use case is memory-mapping BPF array maps, created to back global data variables, created by libbpf implicitly. This allows for much better usability, along with avoiding syscalls to read or update data completely. Due to memory-mapping requirements, BPF array map that is supposed to be memory-mapped, has to be created with special BPF_F_MMAPABLE attribute, which triggers slightly different memory allocation strategy internally. See patch 1 for details. Libbpf is extended to detect kernel support for this flag, and if supported, will specify it for all global data maps automatically. Andrii Nakryiko (3): bpf: add mmap() support for BPF_MAP_TYPE_ARRAY libbpf: make global data internal arrays mmap()-able, if possible selftests/bpf: add BPF_TYPE_MAP_ARRAY mmap() tests include/linux/bpf.h | 8 +- include/uapi/linux/bpf.h | 3 + kernel/bpf/arraymap.c | 96 ++++++++++- kernel/bpf/syscall.c | 39 +++++ tools/include/uapi/linux/bpf.h | 3 + tools/lib/bpf/libbpf.c | 31 +++- .../selftests/bpf/prog_tests/core_reloc.c | 45 +++-- tools/testing/selftests/bpf/prog_tests/mmap.c | 154 ++++++++++++++++++ tools/testing/selftests/bpf/progs/test_mmap.c | 31 ++++ 9 files changed, 380 insertions(+), 30 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/mmap.c create mode 100644 tools/testing/selftests/bpf/progs/test_mmap.c -- 2.17.1
