Re: RFC: mpsafe bridge and NIC drivers (vioif and wm)

[Darren Reed <darrenr%netbsd.org@localhost>]

On 21/06/2014 11:00 AM, Matt Thomas wrote:
> On Jun 20, 2014, at 5:57 AM, Ryota Ozaki <ozaki-r%iij.ad.jp@localhost> wrote:
>
>> Hi,
>>
>> I've prepared a trial patch of MPSAFE networking.
>>
>>  http://www.netbsd.org/~ozaki-r/mpsafe-wm.diff
>>
> The kmutex_t in ifqueue, etc. should be pointers and not in the structure 
> themselves.
> That can simply the macros to test for a NULL pointer for the locks in the 
> non-WM case.
>
> Consider using mutex_obj_alloc to get mutexes instead of the embedding them 
> in the
> structures.

This coding pattern goes against what is done almost everywhere else.

What's the rationale behind it?

Darren