[PATCH] arm64: perf: Fix the userspace counter example link

[TAKANO Mitsuhiro <takano32@gmail.com>]

Documentation/arch/arm64/perf.rst points at
tools/perf/arch/arm64/tests/user-events.c, in the text and in the link
target, but the file does not exist: no file of that name is in
tools/perf/arch/arm64/tests/, and no commit in the history leading to
this base has added one.

The userspace register access described in this section is covered by
the "User space counter reading of instructions" and "User space
counter reading of cycles" cases in tools/perf/tests/mmap-basic.c.
That file is the only in-tree userspace test that walks the core PMUs,
pins the test task to each PMU's CPUs, and selects the PMU by its type
number when the kernel accepts the extended type.

perf test -v user runs the four cases in that file; the two reading
cases ask for user access through config1.

Point the text and the link target at that file.

make htmldocs does not fetch external links, so a plain documentation
build does not report it, but make linkcheckdocs does.  I checked that
the old link target returns 404 and the new one returns 200.  No kernel
was built.

The edit and this changelog were written with the help of an LLM
assistant (Hermes Agent).  I reviewed the diff and the reasoning, and I
am responsible for the submission.

Fixes: aa1005d15d2a ("Documentation: arm64: Document PMU counters access from userspace")
Signed-off-by: TAKANO Mitsuhiro <takano32@gmail.com>
---
 Documentation/arch/arm64/perf.rst | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/Documentation/arch/arm64/perf.rst b/Documentation/arch/arm64/perf.rst
index 997fd716b82f..236cb5da425a 100644
--- a/Documentation/arch/arm64/perf.rst
+++ b/Documentation/arch/arm64/perf.rst
@@ -140,9 +140,9 @@ only be enabled when the tasks are pinned to a homogeneous subset of cores and
 the corresponding PMU instance is opened by specifying the 'type' attribute.
 The use of generic event types is not supported in this case.
 
-Have a look at `tools/perf/arch/arm64/tests/user-events.c`_ for an example. It
-can be run using the perf tool to check that the access to the registers works
-correctly from userspace:
+Have a look at `tools/perf/tests/mmap-basic.c`_ for an example. The two
+'User space counter reading' tests in it can be run using the perf tool to
+check that the access to the registers works correctly from userspace:
 
 .. code-block:: sh
 
@@ -160,8 +160,8 @@ userspace must treat the upper 32-bits read from the counter as UNKNOWN. The
 and should be used to mask the upper bits as needed.
 
 .. Links
-.. _tools/perf/arch/arm64/tests/user-events.c:
-   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/perf/arch/arm64/tests/user-events.c
+.. _tools/perf/tests/mmap-basic.c:
+   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/perf/tests/mmap-basic.c
 .. _tools/lib/perf/tests/test-evsel.c:
    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/lib/perf/tests/test-evsel.c
 

base-commit: d48723711bae9b8cdc56719c448ba42fef28cbee
-- 
2.53.0