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Re: Some help on fast softint stuff...



Matt Thomas wrote:
On May 11, 2010, at 12:25 PM, Johnny Billquist wrote:

Johnny Billquist wrote:
I'm trying to understand, trace, and figure out a few things. I'm wondering a 
bit about softint_dispatch(), and hope someone can answer this.
When reading through the code, I got the feeling that you should always be at 
SPL_HIGH when getting into this function, but occasionally I can see that it 
gets called at another IPL on the VAX.
Is that ok? I cannot find a definitive answer right now as I am searching 
around...
Hmm, answering myself...

softint_dispatch() calls softint_execute() which definitely is documented as 
must be called at splhigh.

So there would seem to be either a bug in the VAX, or else a bug in the 
documentation for softint_execute().

Anyone who can answer which it is.

So far, I've only seen softint_dispatch() being called at SPL_HIGH and SPL_SCHED

The latter, it would seem, is not correct?

And I even know why now that you mention it.  Fix committed.

Great. That change made sense to me. :-)
Testing with a similar fix myself (but cruder), and so far, the 8650 have been happier, it seems.

        Johnny


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