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    SubjectRe: [PATCH] make atomic_t volatile on all architectures
    On Thu, Aug 09, 2007 at 03:31:10AM -0400, Chris Snook wrote:
    > Linus Torvalds wrote:
    > > I'd be *much* happier with "atomic_read()" doing the "volatile" instead.
    > > The fact is, volatile on data structures is a bug. It's a wart in the C
    > > language. It shouldn't be used. Volatile accesses in *code* can be ok, and
    > > if we have "atomic_read()" expand to a "*(volatile int *)&(x)->value", then
    > > I'd be ok with that.
    > > But marking data structures volatile just makes the compiler screw up
    > > totally, and makes code for initialization sequences etc much worse.
    > > Linus
    > Fair enough. Casting to (volatile int *) will give us the behavior people
    > expect when using atomic_t without needing to use inefficient barriers.
    > While we have the hood up, should we convert all the atomic_t's to
    > non-volatile and put volatile casts in all the atomic_reads? I don't know
    > enough about the various arches to say with confidence that those changes
    > alone will preserve existing behavior. We might need some arch-specific
    > tweaking of the atomic operations.

    If you write that patch could you include the atomic64 variants as well,
    please? Besides that just post the patch to linux-arch and maintainers
    should speak up.
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      Last update: 2007-08-09 10:17    [W:0.020 / U:39.744 seconds]
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