Re: [PATCH -v5][RFC]: mutex: implement adaptive spinning

Steven Rostedt
2009-01-08T03:38:36Z

On Wed, 7 Jan 2009, Gregory Haskins wrote:
>
> In my defense, the -rt versions of the patches guarantee this is ok
> based on a little hack:

The -rt versions worry about much more than what the mutex code in
mainline does. Linus is correct in his arguments. The adaptive mutex (as
suppose to what -rt has), is only to help aid in preformance. There are a
lot of races that can happen in mainline version where lock taking may not
be fifo, or where we might start to schedule when we could have taken the
lock. These races are not in -rt, but that is because -rt cares about
these. But mainline cares more about performance over determinism. This
means that we have to look at the current code that Peter is submitting
with a different perspective than we do in -rt.

-- Steve