3 files changed, 50 insertions, 7 deletions
diff --git a/Documentation/technical/api-config.txt b/Documentation/technical/api-config.txt
index 0d8b99b368..20741f345e 100644
--- a/Documentation/technical/api-config.txt
+++ b/Documentation/technical/api-config.txt
@@ -63,13 +63,6 @@ parse for configuration, rather than looking in the usual files. Regular
 Specify whether include directives should be followed in parsed files.
 Regular `git_config` defaults to `1`.
 
-There is a special version of `git_config` called `git_config_early`.
-This version takes an additional parameter to specify the repository
-config, instead of having it looked up via `git_path`. This is useful
-early in a Git program before the repository has been found. Unless
-you're working with early setup code, you probably don't want to use
-this.
-
 Reading Specific Files
 ----------------------
 
diff --git a/Documentation/technical/api-parse-options.txt b/Documentation/technical/api-parse-options.txt
index 5f0757dcc9..695bd4bf43 100644
--- a/Documentation/technical/api-parse-options.txt
+++ b/Documentation/technical/api-parse-options.txt
@@ -231,6 +231,13 @@ There are some macros to easily define options:
 	pass the command-line option, which can be specified multiple times,
 	to another command.
 
+`OPT_CMDMODE(short, long, &int_var, description, enum_val)`::
+	Define an "operation mode" option, only one of which in the same
+	group of "operating mode" options that share the same `int_var`
+	can be given by the user. `enum_val` is set to `int_var` when the
+	option is used, but an error is reported if other "operating mode"
+	option has already set its value to the same `int_var`.
+
 
 The last element of the array must be `OPT_END()`.
 
diff --git a/Documentation/technical/api-trace.txt b/Documentation/technical/api-trace.txt
index 097a651d96..389ae16d15 100644
--- a/Documentation/technical/api-trace.txt
+++ b/Documentation/technical/api-trace.txt
@@ -95,3 +95,46 @@ for (;;) {
 }
 trace_performance(t, "frotz");
 ------------
+
+Bugs & Caveats
+--------------
+
+GIT_TRACE_* environment variables can be used to tell Git to show
+trace output to its standard error stream. Git can often spawn a pager
+internally to run its subcommand and send its standard output and
+standard error to it.
+
+Because GIT_TRACE_PERFORMANCE trace is generated only at the very end
+of the program with atexit(), which happens after the pager exits, it
+would not work well if you send its log to the standard error output
+and let Git spawn the pager at the same time.
+
+As a work around, you can for example use '--no-pager', or set
+GIT_TRACE_PERFORMANCE to another file descriptor which is redirected
+to stderr, or set GIT_TRACE_PERFORMANCE to a file specified by its
+absolute path.
+
+For example instead of the following command which by default may not
+print any performance information:
+
+------------
+GIT_TRACE_PERFORMANCE=2 git log -1
+------------
+
+you may want to use:
+
+------------
+GIT_TRACE_PERFORMANCE=2 git --no-pager log -1
+------------
+
+or:
+
+------------
+GIT_TRACE_PERFORMANCE=3 3>&2 git log -1
+------------
+
+or:
+
+------------
+GIT_TRACE_PERFORMANCE=/path/to/log/file git log -1
+------------