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From: Andrii Nakryiko <andrii@kernel.org>
To: linux-fsdevel@vger.kernel.org,
	brauner@kernel.org,
	viro@zeniv.linux.org.uk,
	akpm@linux-foundation.org
Cc: linux-kernel@vger.kernel.org,
	bpf@vger.kernel.org,
	gregkh@linuxfoundation.org,
	linux-mm@kvack.org,
	Andrii Nakryiko <andrii@kernel.org>
Subject: [PATCH 0/5] ioctl()-based API to query VMAs from /proc/<pid>/maps
Date: Fri,  3 May 2024 17:30:01 -0700
Message-ID: <20240504003006.3303334-1-andrii@kernel.org>
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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