Re: [RFC patch 08/18] cnt32_to_63 should use smp_rmb()

Mathieu Desnoyers
2008-11-07T18:48:12Z

* Harvey Harrison (harvey.harrison@gmail.com) wrote:
> On Fri, 2008-11-07 at 10:21 -0800, Andrew Morton wrote:
> > On Fri, 7 Nov 2008 13:00:41 -0500
> > Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> wrote:
> > > > 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.
> >
> > Referring to include/linux/tracepoint.h:DEFINE_TRACE()?
> >
> > It does look a bit fragile. Does every .c file which included
> > include/trace/block.h get a copy of __tracepoint_block_rq_issue,
> > whether or not it used that tracepoint? Hopefully not.
> >
> > > 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
> > > declarations).
>
> Could this scheme also help with the thousands of sparse warnings that
> kmemtrace produces because of the current arrangement, all of the form:
>
> include/linux/kmemtrace.h:33:2: warning: Initializer entry defined twice
> include/linux/kmemtrace.h:33:2: also defined here
>
> As you could have unique names for the tracepoints now, rather than the
> 'unique' static storage? Or am I off-base here?
>

Exactly.

Mathieu

> Harvey
>
>
>

--
Mathieu Desnoyers
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