perf: clarify some of the custom behavior of `perfrevlogwrite`
This reduce the chance of developers being surprised by special cases.
--- a/contrib/perf.py Wed Jun 12 16:56:41 2019 +0100
+++ b/contrib/perf.py Wed Jun 12 17:30:24 2019 +0100
@@ -2093,6 +2093,16 @@
(use a delta from the first parent otherwise)
* `parent-smallest`: add from the smallest delta (either p1 or p2)
* `storage`: add from the existing precomputed deltas
+
+ Note: This performance command measures performance in a custom way. As a
+ result some of the global configuration of the 'perf' command does not
+ apply to it:
+
+ * ``pre-run``: disabled
+
+ * ``profile-benchmark``: disabled
+
+ * ``run-limits``: disabled use --count instead
"""
opts = _byteskwargs(opts)