Documentation: Update ftrace-design.txt
Correct grammos. Spell out words. Add missing words.
Consistent use of "mcount()" function name.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4B2C0D78.6060707@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/Documentation/trace/ftrace-design.txt b/Documentation/trace/ftrace-design.txt
index 641a1ef..239f14b 100644
--- a/Documentation/trace/ftrace-design.txt
+++ b/Documentation/trace/ftrace-design.txt
@@ -53,14 +53,14 @@
For example, if the function foo() calls bar(), when the bar() function calls
mcount(), the arguments mcount() will pass to the tracer are:
"frompc" - the address bar() will use to return to foo()
- "selfpc" - the address bar() (with _mcount() size adjustment)
+ "selfpc" - the address bar() (with mcount() size adjustment)
Also keep in mind that this mcount function will be called *a lot*, so
optimizing for the default case of no tracer will help the smooth running of
your system when tracing is disabled. So the start of the mcount function is
-typically the bare min with checking things before returning. That also means
-the code flow should usually kept linear (i.e. no branching in the nop case).
-This is of course an optimization and not a hard requirement.
+typically the bare minimum with checking things before returning. That also
+means the code flow should usually be kept linear (i.e. no branching in the nop
+case). This is of course an optimization and not a hard requirement.
Here is some pseudo code that should help (these functions should actually be
implemented in assembly):
@@ -131,10 +131,10 @@
The mcount function should check the function pointers ftrace_graph_return
(compare to ftrace_stub) and ftrace_graph_entry (compare to
-ftrace_graph_entry_stub). If either of those are not set to the relevant stub
+ftrace_graph_entry_stub). If either of those is not set to the relevant stub
function, call the arch-specific function ftrace_graph_caller which in turn
calls the arch-specific function prepare_ftrace_return. Neither of these
-function names are strictly required, but you should use them anyways to stay
+function names is strictly required, but you should use them anyway to stay
consistent across the architecture ports -- easier to compare & contrast
things.
@@ -144,7 +144,7 @@
located on the stack. This allows the function to hijack the return address
temporarily to have it point to the arch-specific function return_to_handler.
That function will simply call the common ftrace_return_to_handler function and
-that will return the original return address with which, you can return to the
+that will return the original return address with which you can return to the
original call site.
Here is the updated mcount pseudo code: