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 <l...@isovalent.com> --- 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-v2-0-95c271434...@isovalent.com 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-aa2724572...@isovalent.com --- 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 | 37 ++++++++++ tools/lib/bpf/btf.c | 83 +++++++++++++++++++--- tools/testing/selftests/bpf/prog_tests/btf_sysfs.c | 83 ++++++++++++++++++++++ 4 files changed, 194 insertions(+), 12 deletions(-) --- base-commit: 38d976c32d85ef12dcd2b8a231196f7049548477 change-id: 20250501-vmlinux-mmap-2ec5563c3ef1 Best regards, -- Lorenz Bauer <l...@isovalent.com>
