Indicate in the docs which options can impact performance

Author: cichli

doc/repl/basic_usage.md

@@ -50,9 +50,10 @@ Please, avoid killing REPL buffers with <kbd>C-c C-k</kbd>
 ## Known Limitations
 
 Performance can degrade when the REPL buffer grows very large. This is
-especially true if `cider-repl-use-clojure-font-lock` is enabled. You can use
-`cider-repl-clear-output` to either clear the result of the previous evaluation,
-or with a prefix argument clear the entire REPL buffer.
+especially true if either `cider-repl-use-clojure-font-lock` or
+`nrepl-log-messages` are enabled. You can use `cider-repl-clear-output` to
+either clear the result of the previous evaluation, or with a prefix argument
+clear the entire REPL buffer.
 
 Very long lines are guaranteed to bring Emacs to a crawl, so using a value of
 `cider-print-fn` that wraps lines beyond a certain width (i.e. any of the

doc/repl/configuration.md

@@ -141,6 +141,8 @@ use:
 (setq cider-repl-use-clojure-font-lock nil)
 ```
 
+Note that enabling font-locking in the REPL can negatively impact performance.
+
 ## Pretty printing in the REPL
 
 By default the REPL always prints the results of your evaluations using the

doc/troubleshooting.md

@@ -68,9 +68,11 @@ you can step forward until you find the problem.
 
 ### Missing `*nrepl-messages*` buffer
 
-nREPL message logging is not enabled by default.  Set `nrepl-log-messages` to
-`t` to activate it. Alternatively you can use <kbd>M-x</kbd> `nrepl-toggle-message-logging`
-to enable/disable logging temporary within your current Emacs session.
+nREPL message logging is not enabled by default. Set `nrepl-log-messages` to `t`
+to activate it. Alternatively you can use <kbd>M-x</kbd>
+`nrepl-toggle-message-logging` to enable/disable logging temporary within your
+current Emacs session. Note that enabling message logging can impact
+performance.
 
 ### `cider-debug` complains that it “failed to instrument ...”