FYI, this case was approved at PSARC this week, with the understanding
that you'll pass the mblk to the free function.
-- Garrett
Garrett D'Amore wrote:
> Paul Durrant wrote:
>> Garrett D'Amore wrote:
>>> I like the idea of the free_func getting passed a third argument,
>>> which is the mblk_t * associated. Then nobody needs to look at
>>> db_mblk. I confess that I'd also feel better if the framework code
>>> reset the mblk fields to default, so that drivers were not required
>>> to know which fields to change and which not. (The problem is what
>>> happens if sizeof (mblk_t) changes?)
>>>
>>> A way to achieve this without requiring a common switch case might
>>> be to add a new function, msgreset() or somesuch, which just clears
>>> the initial mblk header fields to reasonable defaults. Then the
>>> free routine could call msgreset() before reusing the mblk. Thoughts?
>>
>> I think you're going of at a slight tangent here ;-) There's no need
>> for an extra msgreset() call (although I did consider that option
>> myself) because the dblk_lastfree_xesb() code can reset the mblk_t
>> fields prior to calling free_func(). My code at
>> http://cr.opensolaris.org/~pdurrant/stream shows this; check out
>> http://cr.opensolaris.org/~pdurrant/stream/usr/src/uts/common/io/stream.c.html
>>
>> lines 655-659; they are basically identical to lines 702-706 (in
>> gesballoc()).
>
>
> You've made a good point, and I agree, dblk_lastfree_xesb() is the
> right place to do that.
>
> -- Garrett
>>
>> Paul
>>
>
