| Date | Thu, 18 Feb 2010 11:58:01 +0100 | Subject | Re: [PATCH 08/10] x86-32: support atomic64_t on 386/486 UP/SMP | From | Luca Barbieri <> |
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> 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.
We need the generic version with spinlocks for other architectures, and reusing it is the cheapest way to support 386/486.
We thus get 386/486 SMP for free, and on UP the spinlocks simplify to just IRQ disabling.
The only thing we could do is to #ifdef out the hashed spinlock array in the generic implementation on UP builds, which would save about 1KB of memory. That is independent from this patch though.
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