Re: Memory synchronization vs. interrupt handlers

[Alan Stern]

On Wed, 28 Aug 2013, H. Peter Anvin wrote:

> On 08/28/2013 12:16 PM, Alan Stern wrote:
> > Russell, Peter, and Ingo:
> > 
> > Can you folks enlighten us regarding this issue for some common 
> > architectures?
> > 
> 
> On x86, IRET is a serializing instruction; it guarantees hard
> serialization of absolutely everything.

That answers half of the question.  What about the other half?  Does 
the CPU automatically serialize everything when it takes an interrupt?

> I would expect architectures that have weak memory ordering to put
> appropriate barriers in the IRQ entry/exit code.

Then would it be acceptable to mention this in the memory-barriers.txt 
file?

Alan Stern

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