Re: 2.6.9 rc2 freezing

[Dave Jones]

On Wed, Sep 15, 2004 at 12:06:48PM -0400, Lee Revell wrote:

 > Anyway, if you are running anything on your server that breaks under
 > PREEMPT, it will break anyway as soon as you add another processor.

Wrong. Code can be SMP safe but not preempt safe.
This is why we have get_cpu()/put_cpu(), and
preempt_disable()/preempt_enable() pairs around certain parts of code.

Anything using per-CPU data like MSRs for example needs explicit
protection against preemption.

		Dave

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