Re: [DOCUMENTATION] Revised Unreliable Kernel Locking Guide

[Keith Owens]

On Fri, 12 Dec 2003 15:44:01 +0000, 
Dave Jones <davej@xxxxxxxxxx> wrote:
> Might be worth mentioning in the Per-CPU data section that code doing
>operations on CPU registers (MSRs and the like) needs to be protected
>by an explicit preempt_disable() / preempt_enable() pair if it's doing
>operations that it expects to run on a specific CPU.

Also calls to smp_call_function() need to be wrapped in preempt_disable,
plus any work that is done on the current cpu before/after calling a
function on the other cpus.  Lack of preempt disable could result in
the operation being done twice on one cpu and not at all on another.

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