Re: [PATCH 38 of 39] IB/ipath - More changes to support InfiniPathon PowerPC 970 systems

From: Dave Olson
Date: Thu Jul 13 2006 - 02:00:26 EST


On Thu, 6 Jul 2006, Benjamin Herrenschmidt wrote:

| On Thu, 2006-07-06 at 16:34 -0700, Bryan O'Sullivan wrote:
| > On Fri, 2006-07-07 at 08:37 +1000, Benjamin Herrenschmidt wrote:
| >
| > > > +int ipath_unordered_wc(void)
| > > > +{
| > > > + return 1;
| > > > +}
| > >
| > > How is the above providing any kind of serialisation ?
| >
| > It's not intended to; it tells the *caller* whether to do it.
|
| Ah ok. What barrier do you use for that ?

on x86_64, the sfence instruction, on others, wmb(), in the kernel. In user-land,
pretty much the same underlying assembly instructions.

Dave Olson
olson@xxxxxxxxxxxx
http://www.unixfolk.com/dave
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