Received-SPF: pass (google.com: domain of linux-kernel+bounces-209692-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
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,
	liam.howlett@oracle.com,
	surenb@google.com,
	rppt@kernel.org,
	Andrii Nakryiko <andrii@kernel.org>
Subject: [PATCH v4 4/7] docs/procfs: call out ioctl()-based PROCMAP_QUERY command existence
Date: Tue, 11 Jun 2024 04:00:52 -0700
Message-ID: <20240611110058.3444968-5-andrii@kernel.org>
In-Reply-To: <20240611110058.3444968-1-andrii@kernel.org>
References: <20240611110058.3444968-1-andrii@kernel.org>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

Call out PROCMAP_QUERY ioctl() existence in the section describing
/proc/PID/maps file in documentation. We refer user to UAPI header for
low-level details of this programmatic interface.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
 Documentation/filesystems/proc.rst | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
index 7c3a565ffbef..3a86d12c881f 100644
--- a/Documentation/filesystems/proc.rst
+++ b/Documentation/filesystems/proc.rst
@@ -443,6 +443,15 @@ is not associated with a file:
 
  or if empty, the mapping is anonymous.
 
+Starting with 6.11 kernel, /proc/PID/maps provides an alternative
+ioctl()-based API that gives ability to flexibly and efficiently query and
+filter individual VMAs. This interface is binary and is meant for more
+efficient and easy programmatic use. `struct procmap_query`, defined in
+linux/fs.h UAPI header, serves as an input/output argument to the
+`PROCMAP_QUERY` ioctl() command. See comments in linus/fs.h UAPI header for
+details on query semantics, supported flags, data returned, and general API
+usage information.
+
 The /proc/PID/smaps is an extension based on maps, showing the memory
 consumption for each of the process's mappings. For each mapping (aka Virtual
 Memory Area, or VMA) there is a series of lines such as the following::
-- 
2.43.0