svn commit: r275136 - in head/sys: dev/e1000 dev/ixgbe kern sys

[Hans Petter Selasky]

On 12/01/14 16:39, Alfred Perlstein wrote:
>
>
>> On Dec 1, 2014, at 7:34 AM, Hans Petter Selasky <hps at selasky.org> wrote:
>>
>>> On 12/01/14 16:29, Alfred Perlstein wrote:
>>>
>>>
>>>>> On Dec 1, 2014, at 7:26 AM, Hans Petter Selasky <hps at selasky.org> wrote:
>>>>>
>>>>> On 12/01/14 16:19, Alfred Perlstein wrote:
>>>>> It makes little sense to have a rw sysctl that only takes effect "some times". This violates POLA at the expense of making code appear cleaner. Expectation is that writable sysctls take
>>>>
>>>> Hi,
>>>>
>>>> I think you are missing a new feature in 11-current, that if you add "CTLFLAG_TUN" to even dynamic sysctls, they get initialized from the enviroment, if any. That way you can just skip the TUNABLE_INT_FETCH() stuff!
>>>
>>> Ok I can probably switch to that.
>>>
>>> Any objection if I mfc this feature to -stable if it does what I need?
>>
>> Hi,
>>
>> No objections from me at least, but it might require some work from your side, because there was a lot of cleanup about removing duplicate definitions, like static SYSCTLS which have already CTLFLAG_TUN and a TUNABLE fetch statement, which makes the variable init twice. Just look at the revision history for "kern/kern_sysctl.c" in 11-current.
>>
>> --HPS
>>
>>
>
> One question though... For the global sysctl for all nodes....
>
> When is the var fetched?  If it's before SI_SUB_CPU it is not useful.
>

Hi,

It is quite early, actually:

SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_FIRST, sysctl_register_all, 0);

In some parts of the machine independent, MI, code you neee to keep the 
TUNABLE_FETCH'es, because its run before SI_SUB_KMEM !

--HPS