Re: Kernel oops with 2.6.26, padlock and ipsec: probably problemwith fpu state changes

[H. Peter Anvin]

Herbert Xu wrote:
> On Fri, Aug 08, 2008 at 12:01:15PM -0700, H. Peter Anvin wrote:
> > It's technically overkill, if (and only if!) these instructions don't 
> > actually touch the SSE state (most likely they're using the SSE 
> > pipeline, and need this stuff to deal with power management issues.)
>
> Yes the PadLock uses the SSE pipeline, but doesn't touch any
> of the state.

And yet it requires all the settings that goes along with holding the 
SSE state.  Really crap design, unfortunately.

> > However, overkill is a good way to make sure something is dead. 
> > Applying the patch will make sure we fix the regression, and we can 
> > worry about optimizing this further post-2.6.27.
>
> Do we really need the FPU changes right now? I'd prefer for that
> to be backed out until a proper solution is found.  Disabling
> preemption around crypto is really bad for scheduling latency.

I hate to say it, but given the relative marketshare, we should disable 
Padlock instead.

This is part of the pain of being a minority architecture.

	-hpa

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