powernow regression in 8-STABLE

Callum Gibson callumgibson at optusnet.com.au
Sat Jul 23 08:13:07 UTC 2011

On 22Jul11 08:16, John Baldwin wrote:
}The problem is that we calibrate the TSC using this algorithm:
} - grab the TSC
} - spin on the ISA timer waiting for it to run for a second
} - grab the TSC
}The issue is that the SMI# fires at the same time we want to be execuiting 
}step 3, and step 3 is deferred while the SMI# handler runs.  As a result, the 
}TSC delta ends up being "1 second + time of an SMI# to poll USB".  We have a 
}hack fix for this at work that originally came from Attilio Rao.  This is a 
}patch for it relative to 8.  It disables interrupt generation for the ISA 
}timer while we calibrate the TSC (which disables the SMI# temporarily):

Thanks, John. The hack works as intended, but I guess it's not a "real"
solution which is why you haven't committed it?



Callum Gibson @ home

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