Messages in this thread | | | From | David Howells <> | Subject | Re: [RFC patch 08/18] cnt32_to_63 should use smp_rmb() | Date | Fri, 07 Nov 2008 23:50:38 +0000 |
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Steven Rostedt <rostedt@goodmis.org> wrote:
> > I use smp_rmb() to do this on SMP systems (hrm, actually, a rmb() could > > be required so it works also on UP systems safely wrt interrupts). > > smp_rmb turns into a compiler barrier on UP and should prevent the below > description.
Note that that does not guarantee that the two reads will be done in the order you want. The compiler barrier _only_ affects the compiler. It does not stop the CPU from doing the reads in any order it wants. You need something stronger than smp_rmb() if you need the reads to be so ordered.
David
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