Messages in this thread | | | Date | Thu, 09 Aug 2007 12:54:10 -0400 | From | Chris Snook <> | Subject | Re: [PATCH 6/24] make atomic_read() behave consistently on frv |
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Chris Snook wrote: > From: Chris Snook <csnook@redhat.com> > > Make atomic_read() volatile on frv. This ensures that busy-waiting > for an interrupt handler to change an atomic_t won't get compiled to an > infinite loop, consistent with SMP architectures.
To head off the criticism, I admit this is an oversimplification, and true busy-waiters should be using cpu_relax(), which contains a barrier. As discussed in recent threads, there are other cases which can be optimized by removing the need for a barrier, and having behavior consistent with architectures where the benefit is more profound is also valuable.
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