update test/perf README (fix JuliaLang#19853)

test/perf/README.md

@@ -1,8 +1,15 @@
 Julia performance monitoring
 ============================
 
-This directory contains tests and related utilities to monitor Julia's
-performance over time.
+This directory contains benchmarks and related utilities to test Julia's
+performance. Many of these benchmarks have been ported to the newer
+[BaseBenchmarks package](https://github.com/JuliaCI/BaseBenchmarks.jl),
+which contains the benchmark suite used for CI performance testing.
+In general, new benchmarks should be added to that package instead
+of placed here (see the BaseBenchmarks README for details).
+
+If you'd like to test the performance of your own package, consider using
+the [BenchmarkTools package](https://github.com/JuliaCI/BenchmarkTools.jl).
 
 Running the performance tests
 -----------------------------
@@ -15,10 +22,11 @@ test runs in micro seconds.
 There is also a `perfcomp.jl` script but it may not be working with
 the rest at the moment.
 
-Adding tests
-------------
-First decide whether the new tests should go into one of the existing
-suites:
+Code Organization
+-----------------
+
+Tests generally go into one of the following suites:
+
 - `micro`: A set of micro-benchmarks commonly used to compare
  programming languages; these results are shown on
  [http:https://julialang.org/](http:https://julialang.org/).
@@ -36,28 +44,20 @@ suites:
  [Peter Norvig's spelling corrector](http:https://norvig.com/spell-correct.html).
 - `sparse`: Performance tests of sparse matrix operations.
 
-Otherwise add a subdirectory containing the file `perf.jl` and
-update the `Makefile` as well.
+Otherwise tests live in their own subdirectories containing a `perf.jl` file.
 
-In `perf.jl`, `include("../perfutil.jl")` and then run the
-performance test functions with the `@timeit` macro. For example:
+The `perf.jl` files include the shared performance utilies via
+`include("../perfutil.jl")`, and then run the performance test
+functions with the `@timeit` macro. For example:
 ```julia
 @timeit(spelltest(tests1), "spell", "Peter Norvig's spell corrector")
 ```
 with arguments: test function call, name of the test, description,
-and, optionally, a group (only used for codespeed). `@timeit` will do
-a warm-up and then 5 timings, calculating min, max, average and standard
-deviation of the timings.
-
-If possible aim for the tests to take about 10-100 microseconds.
-
-Using the framework for your own tests
---------------------------------------
-
-Just include `perfutil.jl`, use `@timeit` on the functions to be
-benchmarked. Alternatively have a look at the
-[BenchmarkTools package](https://github.com/JuliaCI/BenchmarkTools.jl).
+and, optionally, a group. `@timeit` will do a warm-up and then 5
+timings, calculating min, max, average and standard deviation of
+the timings.
 
+If possible, the tests aim to take about 10-100 microseconds.
 
 Package dependencies
 --------------------