Messages in this thread | | | Date | Thu, 18 Feb 2010 07:20:38 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH 08/10] x86-32: support atomic64_t on 386/486 UP/SMP |
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On 02/18/2010 02:25 AM, Peter Zijlstra wrote: > On Wed, 2010-02-17 at 12:42 +0100, Luca Barbieri wrote: >> This patch makes atomic64 use either the generic implementation or >> the rewritten cmpxchg8b one just introduced by inserting a "call" to >> either, using the alternatives system to dynamically switch the calls. >> >> This allows to use atomic64_t on 386/486 which lack cmpxchg8b > > IIRC we dropped <i586 SMP support, and since we don't have a PMU on > those chips atomic64_t doesn't need to be NMI safe, so a simple > UP-IRQ-disable implementation should suffice.
... which is what we have now, with the cmpxchg8b alternates emulation.
-hpa
-- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.
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