WITNESS bug

[Julian Elischer]

John Baldwin wrote:

>On Tuesday 19 October 2004 12:01 pm, Kris Kennaway wrote:
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>
>>On Tue, Oct 19, 2004 at 09:13:26AM -0400, Robert Huff wrote:
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>>>Brian Fundakowski Feldman writes:
>>>      
>>>
>>>> You should never not run with WITNESS_SKIPSPIN if you use
>>>> modules.  Any spin mutexes not listed statically in the witness
>>>> code will cause your machine to immediately panic.
>>>>        
>>>>
>>>	If this is true (and I'm not disputing it), shouldn't it be
>>>noted in GENERIC and/or NOTES?  For that matter, what's the penalty
>>>for not automatically including it as part of WITNESS?
>>>      
>>>
>>Sometimes you don't want to use it, e.g. if you actually want to trace
>>spinlock operations with witness.
>>    
>>
>
>True spin mutexes should be rarely used anyways, so I don't think modules 
>needing spin mutexes is all that big of an issue.  Almost all mutexes should 
>just be regular mutexes.
>

netgraph uses a spin mutex for it's node locks

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