Messages in this thread | | | Date | Fri, 10 Aug 2007 15:54:19 -0400 | From | Chris Snook <> | Subject | Re: [PATCH 6/24] make atomic_read() behave consistently on frv |
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David Howells wrote: > Chris Snook <csnook@redhat.com> wrote: > >> To head off the criticism, I admit this is an oversimplification, and true >> busy-waiters should be using cpu_relax(), which contains a barrier. > > Why would you want to use cpu_relax()? That's there to waste time efficiently, > isn't it? Shouldn't you be using smp_rmb() or something like that? > > David
cpu_relax() contains a barrier, so it should do the right thing. For non-smp architectures, I'm concerned about interacting with interrupt handlers. Some drivers do use atomic_* operations.
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