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

Alfred Perlstein bright at mu.org
Mon Dec 1 15:45:05 UTC 2014



> On Dec 1, 2014, at 7:43 AM, Hans Petter Selasky <hps at selasky.org> wrote:
> 
>> 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 !

Then it will not work unless I move the global n_queues sysctl creation into the driver's mod load function. 

Is that ok?



> 
> --HPS
> 
> 
> 


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