[PATCH 3/4] docs: admin-guide: clarify perf bench all behavior

[Cheng-Han Wu]

The workload tracing guide lists a fixed set of benchmarks for
"perf bench all". This list is stale and can become outdated when
perf adds, removes, or renames benchmark collections or individual
benchmarks.

Describe "perf bench all" as running all available benchmarks in the perf
bench framework instead. Also document how to list the collections and
benchmarks available on a given system.

Signed-off-by: Cheng-Han Wu <hank20010209@xxxxxxxxx>
---
 .../admin-guide/workload-tracing.rst          | 20 +++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/Documentation/admin-guide/workload-tracing.rst b/Documentation/admin-guide/workload-tracing.rst
index 43a3c8098654..c49c2a00a8b8 100644
--- a/Documentation/admin-guide/workload-tracing.rst
+++ b/Documentation/admin-guide/workload-tracing.rst
@@ -243,13 +243,21 @@ which can help mitigate performance regressions. It also acts as a common
 benchmarking framework, enabling developers to easily create test cases,
 integrate transparently, and use performance-rich tooling.
 
-"perf bench all" command runs the following benchmarks:
+"perf bench all" runs all available benchmarks in the perf bench
+framework. The exact set of benchmarks depends on the perf version and on
+the features enabled when perf was built.
 
- * sched/messaging
- * sched/pipe
- * syscall/basic
- * mem/memcpy
- * mem/memset
+To list the benchmark collections available on the current system, run::
+
+  perf bench
+
+To list benchmarks in a collection, run::
+
+  perf bench <collection>
+
+For example, to list the benchmarks in the mem collection, run::
+
+  perf bench mem
 
 What is stress-ng and how do we use it?
 =======================================
-- 
2.52.0