Re: [PATCH RFC 00/11] lock monitor: Separate features related tolock

[Hitoshi Mitake]

On 03/19/10 06:16, Frederic Weisbecker wrote:
>> And I have a question related to this dynamic patching approach for 
lockdep.
>> If dynamic proving turning on/off is provided,
>> lockdep will be confused by inconsistency of lock acquiring log.
>>
>> Will the sequence,
>>
>> lock_acquire(l) ->  turning off ->  lock_release(l) ->  turning on ->
>> lock_acquire(l)
>>
>> detected as double acquiring?
>>
>> Should turning on/off lockdep be done in the time
>> when every processes have no lock?
>
>
> There is almost always a process with a lock somewhere ;-)

Yeah :)

>
> This is not a big deal, it's very similar to unfinished scenarios
> due to the end of the tracing that can happen anytime and you miss
> a lock_release or whatever. We can also begin the tracing anytime,
> and you may receive orphan lock_release in the very beginning
> because you missed the lock_acquire that happened before the tracing.
>
> Any locking scenario that doesn't fit into the state machine
> or is incomplete must be considered as broken and then ignored.
>
>

I see, thanks.
I have to fix state machine of perf lock.
Now it doesn't consider read, try and orphan events,
it is very incompletely..
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