Re: struct ifnet locking [was Re: IFEF_MPSAFE]

[Ryota Ozaki <ozaki.ryota%gmail.com@localhost>]

On Mon, Nov 27, 2017 at 12:24 AM, Nick Hudson <skrll%netbsd.org@localhost> wrote:
> On 11/17/17 07:44, Ryota Ozaki wrote:
>>
>> On Wed, Nov 15, 2017 at 1:53 PM, Ryota Ozaki <ozaki.ryota%gmail.com@localhost>
>> wrote:
>>>
>>> On Fri, Nov 10, 2017 at 6:35 PM, Ryota Ozaki <ozaki.ryota%gmail.com@localhost>
>>> wrote:
>>>>
>>>> Hi,
>>>>
>>>> http://www.netbsd.org/~ozaki-r/IFEF_MPSAFE.diff
>>>>
>>>> I'm going to commit the above change that integrates
>>>> IFEF_OUTPUT_MPSAFE and IFEF_START_MPSAFE flags into
>>>> IFEF_MPSAFE.
>>>>
>>>> The motivation is to not waste if_extflags bits. I'm now
>>>> trying to make if_ioctl() hold KERNEL_LOCK selectively
>>>> for some reasons as well as if_start() and if_output().
>>>
>>> BTW this is a patch for this plan:
>>>    http://www.netbsd.org/~ozaki-r/if_ioctl-no-KERNEL_LOCK.diff
>>>
>>> It removes KERNEL_LOCK for if_ioctl from soo_ioctl and
>>> selectively takes it in doifioctl. To this end, some fine-grain
>>> KERNEL_LOCKs have to be added where calling components/functions
>>> that aren't MP-safe.
>>
>> Revised rebased on latest NET_MPSAFE macros. The new patch also provides
>> similar macros:
>>    http://www.netbsd.org/~ozaki-r/if_ioctl-no-KERNEL_LOCK.revised.diff
>>
>>    ozaki-r
>>
> Hi,

(Sorry for late replying. I was sick in bed for days...)

>
> Can you document the protection requirements of the struct ifnet members,
> e.g. if_flags.
>
> Ideally by annotating it like struct proc
>
> http://src.illumos.org/source/xref/netbsd-src/sys/sys/proc.h#230

OK. I'm trying to add annotations like that.

  ozaki-r