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
>
