Implement binary ioctl()-based interface to /proc/<pid>/maps file to allow applications to query VMA information more efficiently than through textual processing of /proc/<pid>/maps contents. See patch #2 for the context, justification, and nuances of the API design. Patch #1 is a refactoring to keep VMA name logic determination in one place. Patch #2 is the meat of kernel-side API. Patch #3 just syncs UAPI header (linux/fs.h) into tools/include. Patch #4 adjusts BPF selftests logic that currently parses /proc/<pid>/maps to optionally use this new ioctl()-based API, if supported. Patch #5 implements a simple C tool to demonstrate intended efficient use (for both textual and binary interfaces) and allows benchmarking them. Patch itself also has performance numbers of a test based on one of the medium-sized internal applications taken from production. This patch set was based on top of next-20240503 tag in linux-next tree. Not sure what should be the target tree for this, I'd appreciate any guidance, thank you! Andrii Nakryiko (5): fs/procfs: extract logic for getting VMA name constituents fs/procfs: implement efficient VMA querying API for /proc/<pid>/maps tools: sync uapi/linux/fs.h header into tools subdir selftests/bpf: make use of PROCFS_PROCMAP_QUERY ioctl, if available selftests/bpf: a simple benchmark tool for /proc/<pid>/maps APIs fs/proc/task_mmu.c | 290 +++++++++++--- include/uapi/linux/fs.h | 32 ++ .../perf/trace/beauty/include/uapi/linux/fs.h | 32 ++ tools/testing/selftests/bpf/.gitignore | 1 + tools/testing/selftests/bpf/Makefile | 2 +- tools/testing/selftests/bpf/procfs_query.c | 366 ++++++++++++++++++ tools/testing/selftests/bpf/test_progs.c | 3 + tools/testing/selftests/bpf/test_progs.h | 2 + tools/testing/selftests/bpf/trace_helpers.c | 105 ++++- 9 files changed, 763 insertions(+), 70 deletions(-) create mode 100644 tools/testing/selftests/bpf/procfs_query.c -- 2.43.0
