I'd like to cut down the memory usage of parsing vmlinux BTF in ebpf-go. With some upcoming changes the library is sitting at 5MiB for a parse. Most of that memory is simply copying the BTF blob into user space. By allowing vmlinux BTF to be mmapped read-only into user space I can cut memory usage by about 75%.
Signed-off-by: Lorenz Bauer lmb@isovalent.com --- Changes in v5: - Fix error return of btf_parse_raw_mmap (Andrii) - Link to v4: https://lore.kernel.org/r/20250510-vmlinux-mmap-v4-0-69e424b2a672@isovalent....
Changes in v4: - Go back to remap_pfn_range for aarch64 compat - Dropped btf_new_no_copy (Andrii) - Fixed nits in selftests (Andrii) - Clearer error handling in the mmap handler (Andrii) - Fixed build on s390 - Link to v3: https://lore.kernel.org/r/20250505-vmlinux-mmap-v3-0-5d53afa060e8@isovalent....
Changes in v3: - Remove slightly confusing calculation of trailing (Alexei) - Use vm_insert_page (Alexei) - Simplified libbpf code - Link to v2: https://lore.kernel.org/r/20250502-vmlinux-mmap-v2-0-95c271434519@isovalent....
Changes in v2: - Use btf__new in selftest - Avoid vm_iomap_memory in btf_vmlinux_mmap - Add VM_DONTDUMP - Add support to libbpf - Link to v1: https://lore.kernel.org/r/20250501-vmlinux-mmap-v1-0-aa2724572598@isovalent....
--- Lorenz Bauer (3): btf: allow mmap of vmlinux btf selftests: bpf: add a test for mmapable vmlinux BTF libbpf: Use mmap to parse vmlinux BTF from sysfs
include/asm-generic/vmlinux.lds.h | 3 +- kernel/bpf/sysfs_btf.c | 32 ++++++++ tools/lib/bpf/btf.c | 89 +++++++++++++++++----- tools/testing/selftests/bpf/prog_tests/btf_sysfs.c | 81 ++++++++++++++++++++ 4 files changed, 186 insertions(+), 19 deletions(-) --- base-commit: 7220eabff8cb4af3b93cd021aa853b9f5df2923f change-id: 20250501-vmlinux-mmap-2ec5563c3ef1
Best regards,