On Mon, 25 Nov 2019 12:37:09 -0500 Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > On Sun, 24 Nov 2019 23:38:41 -0500 > "Frank A. Cancio Bello" <frank@xxxxxxxxxxxxxxxxxxxxxx> wrote: > > > --- a/Documentation/trace/ring-buffer-design.txt > > +++ b/Documentation/trace/ring-buffer-design.txt > > @@ -37,7 +37,7 @@ commit_page - a pointer to the page with the last finished non-nested write. > > > > cmpxchg - hardware-assisted atomic transaction that performs the following: > > > > - A = B iff previous A == C > > + A = B if previous A == C > > This wasn't a typo. "iff" means "if and only if" which is a standard > notation. That is, this is shorthand for: > > A = B if previous A == C > previous A == C if A = B Although thinking about this more, this may not be correct. If previous A == B, then A = B, thus the "iff" notation is not actually accurate. This wouldn't then be a typo fix, but a real fix to the logic ;-) -- Steve > > > > > > R = cmpxchg(A, C, B) is saying that we replace A with B if and only if > > current A is equal to C, and we put the old (current) A into R > > --
