Re: [PATCH 1/3] sched, timer: Remove usages of ACCESS_ONCE in the scheduler

[Peter Zijlstra]

On Thu, Apr 16, 2015 at 08:24:27PM +0200, Ingo Molnar wrote:
> Yes ... but that still leaves this weird feeling that it's really 
> still a bit wrong because it's not proper parallel code, we just 
> reduced the probability of the remaining races radically. And it's not 
> like GCC (or any compiler) does load tearing or even store tearing 
> under normal -O2 for such code patterns, right?

I think Paul once caught GCC doing something silly, but typically no.
The re-loads however have been frequently observed.

> > And its not like they really cost anything.
> 
> That's true.
> 
> Would it make sense to add a few comments to the seq field definition 
> site(s), about how it's supposed to be accessed - or to the 
> READ_ONCE()/WRITE_ONCE() sites, to keep people from wondering?

For sure, can do a comment no problem.
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