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Date: Tue, 11 Jun 2024 11:59:50 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Andrii Nakryiko <andrii@kernel.org>
Cc: linux-fsdevel@vger.kernel.org, brauner@kernel.org,
 viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org, bpf@vger.kernel.org,
 gregkh@linuxfoundation.org, linux-mm@kvack.org, liam.howlett@oracle.com,
 surenb@google.com, rppt@kernel.org, Alexey Dobriyan <adobriyan@gmail.com>
Subject: Re: [PATCH v4 0/7] ioctl()-based API to query VMAs from
 /proc/<pid>/maps
Message-Id: <20240611115950.35197b36eafe0a804ecaa0de@linux-foundation.org>
In-Reply-To: <20240611110058.3444968-1-andrii@kernel.org>
References: <20240611110058.3444968-1-andrii@kernel.org>
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(Please cc Alexey on procfs changes)

On Tue, 11 Jun 2024 04:00:48 -0700 Andrii Nakryiko <andrii@kernel.org> wrote:

> Implement binary ioctl()-based interface to /proc/<pid>/maps file to allow
> applications to query VMA information more efficiently than reading *all* VMAs
> nonselectively through text-based interface of /proc/<pid>/maps file.

Looks nice but I'll await further reviewer input.

> 
> ...
>
>  Documentation/filesystems/proc.rst          |   9 +
>  fs/proc/task_mmu.c                          | 366 +++++++++++--
>  include/uapi/linux/fs.h                     | 156 +++++-
>  tools/include/uapi/linux/fs.h               | 550 ++++++++++++++++++++
>  tools/testing/selftests/bpf/.gitignore      |   1 +
>  tools/testing/selftests/bpf/Makefile        |   2 +-
>  tools/testing/selftests/bpf/procfs_query.c  | 386 ++++++++++++++
>  tools/testing/selftests/bpf/test_progs.c    |   3 +
>  tools/testing/selftests/bpf/test_progs.h    |   2 +
>  tools/testing/selftests/bpf/trace_helpers.c | 104 +++-
>  10 files changed, 1508 insertions(+), 71 deletions(-)
>  create mode 100644 tools/include/uapi/linux/fs.h
>  create mode 100644 tools/testing/selftests/bpf/procfs_query.c

Should the selftests be under bpf/?  This is a procfs feature which
could be used by many things apart from bpf and it really isn't a bpf
thing at all.  Wouldn't tools/testing/selftests/proc/ be a more
appropriate place?