Re: [PATCH] sched: Change READ_ONCE(jiffies) into jiffies

From: Peter Zijlstra
Date: Mon Sep 26 2016 - 04:55:55 EST

On Sun, Sep 25, 2016 at 07:08:45PM -0700, Bart Van Assche wrote:
> A quote from Documentation/memory_barriers.txt:
> For example, because 'jiffies' is marked volatile, it is never
> necessary to say READ_ONCE(jiffies). The reason for this is
> that READ_ONCE() and WRITE_ONCE() are implemented as volatile
> casts, which has no effect when its argument is already marked
> volatile.
> Hence change all 'READ_ONCE(jiffies)' occurrences into 'jiffies'.

So I'm not a huge fan of this patch. Yes its technically pointless, but
it does convey intent. See the READ_ONCE() as a comment if you will.