v4.19.13 snapshot.
diff --git a/Documentation/trace/function-graph-fold.vim b/Documentation/trace/function-graph-fold.vim
new file mode 100644
index 0000000..0544b50
--- /dev/null
+++ b/Documentation/trace/function-graph-fold.vim
@@ -0,0 +1,42 @@
+" Enable folding for ftrace function_graph traces.
+"
+" To use, :source this file while viewing a function_graph trace, or use vim's
+" -S option to load from the command-line together with a trace. You can then
+" use the usual vim fold commands, such as "za", to open and close nested
+" functions. While closed, a fold will show the total time taken for a call,
+" as would normally appear on the line with the closing brace. Folded
+" functions will not include finish_task_switch(), so folding should remain
+" relatively sane even through a context switch.
+"
+" Note that this will almost certainly only work well with a
+" single-CPU trace (e.g. trace-cmd report --cpu 1).
+
+function! FunctionGraphFoldExpr(lnum)
+ let line = getline(a:lnum)
+ if line[-1:] == '{'
+ if line =~ 'finish_task_switch() {$'
+ return '>1'
+ endif
+ return 'a1'
+ elseif line[-1:] == '}'
+ return 's1'
+ else
+ return '='
+ endif
+endfunction
+
+function! FunctionGraphFoldText()
+ let s = split(getline(v:foldstart), '|', 1)
+ if getline(v:foldend+1) =~ 'finish_task_switch() {$'
+ let s[2] = ' task switch '
+ else
+ let e = split(getline(v:foldend), '|', 1)
+ let s[2] = e[2]
+ endif
+ return join(s, '|')
+endfunction
+
+setlocal foldexpr=FunctionGraphFoldExpr(v:lnum)
+setlocal foldtext=FunctionGraphFoldText()
+setlocal foldcolumn=12
+setlocal foldmethod=expr