Messages in this thread | | | From | David Howells <> | Subject | Re: [PATCH 1/4] arch: local64_t | Date | Fri, 21 May 2010 15:52:29 +0100 |
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Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:
> + * This is the default implementation, which uses atomic64_t. Which is > + * rather pointless. The whole point behind local64_t is that some processors > + * can perform atomic adds and subtracts in a manner which is atomic wrt IRQs > + * running on this CPU. local64_t allows exploitation of such capabilities.
Interesting... What FRV does in atomic64-ops.S should probably be rebranded local64_t, and atomic64_t ops be based on that in non-SMP mode.
What I did on FRV was to emulate LL/ST instructions using some of the excessive numbers of conditional bits to do so - but it only works on UP systems.
David
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