Messages in this thread | | | Date | Tue, 4 Jun 2019 13:00:03 -0400 (EDT) | From | Alan Stern <> | Subject | Re: rcu_read_lock lost its compiler barrier |
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On Tue, 4 Jun 2019, Linus Torvalds wrote:
> So I don't technically disagree with anything you say,
That's good to know!
> I just wanted > to point out that as far as the kernel is concerned, we do have higher > quality expectations from the compiler than just "technically valid > according to the C standard".
Which suggests asking whether these higher expectations should be reflected in the Linux Kernel Memory Model. So far we have largely avoided doing that sort of thing, although there are a few exceptions.
(For example, we assume the compiler does not destroy address dependencies from volatile reads -- but we also warn that this assumption may fail if the programmer does not follow some rules described in one of Paul's documentation files.)
Alan
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