On 03/17/10 18:52, Ingo Molnar wrote:
>
> * Frederic Weisbecker<fweisbec@gmail.com> wrote:
>
>>> You add chained indirect calls into all lock ops, that's got to hurt.
>>
>> Well, the idea was not bad at the first glance. It was separating
lockdep
>> and lock events codes.
>>
>> But indeed, the indirect calls plus the locking are not good for
such a fast
>> path.
>
> What would be nice to have is some sort of dynamic patching approach
to enable
> _both_ lockdep, lockstat and perf lock.
>
> If TRACE_EVENT() tracepoints were patchable we could use them. (but
they arent
> right now)
I'll try it!
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?
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