Messages in this thread | | | Date | Fri, 16 Jan 2009 09:10:15 -0500 | From | Mark Lord <> | Subject | Re: [PATCH] percpu: add optimized generic percpu accessors |
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Andrew Morton wrote: > On Thu, 15 Jan 2009 19:02:59 +0100 Ingo Molnar <mingo@elte.hu> wrote: > >> * Andrew Morton <akpm@linux-foundation.org> wrote: .. >>> I wonder if the preempt_disable()/preempt_enable() in here actually >>> does anything useful on any architecture. >> Provides "this is IRQ safe" > > ? > >> and "this is preempt safe" semantics. > > Of course. But do any architectures actually _need_ that for a single read? ..
If the target is unaligned, then RISC architectures will need protection there. If we can guarantee correct memory alignment of the target, then no / none.
Cheers
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