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    SubjectRe: [RFC patch 08/18] cnt32_to_63 should use smp_rmb()
    * Andrew Morton ( wrote:
    > On Fri, 07 Nov 2008 17:10:00 +0000 David Howells <> wrote:
    > >
    > > Andrew Morton <> wrote:
    > >
    > > > I'd expect it to behave in the same way as it would if the function was
    > > > implemented out-of-line.
    > > >
    > > > But it occurs to me that the modrobe-doesnt-work thing would happen if
    > > > the function _is_ inlined anyway, so we won't be doing that.
    > > >
    > > > Whatever. Killing this many puppies because gcc may do something so
    > > > bizarrely wrong isn't justifiable.
    > >
    > > With gcc, you get one instance of the static variable from inside a static
    > > (inline or outofline) function per .o file that invokes it, and these do not
    > > merge even though they're common symbols. I asked around and the opinion
    > > seems to be that this is correct C. I suppose it's the equivalent of cutting
    > > and pasting a function between several files - why should the compiler assume
    > > it's the same function in each?
    > >
    > OK, thanks, I guess that makes sense. For static inline. I wonder if
    > `extern inline' or plain old `inline' should change it.
    > It's one of those things I hope I never need to know about, but perhaps
    > we do somewhere have static storage in an inline. Wouldn't surprise
    > me, and I bet that if we do, it's a bug.

    Tracepoints actually use that. It could be changed so they use :

    DECLARE_TRACE() (in include/trace/group.h)
    DEFINE_TRACE() (in the appropriate kernel c file)
    trace_somename(); (in the code)

    instead. That would actually make more sense and remove the need for
    multiple declarations when the same tracepoint name is used in many
    spots (this is a problem kmemtrace has, it generates a lot of tracepoint


    Mathieu Desnoyers
    OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68

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