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Date:      Mon, 1 Dec 2014 07:45:03 -0800
From:      Alfred Perlstein <bright@mu.org>
To:        Hans Petter Selasky <hps@selasky.org>
Cc:        "svn-src-head@freebsd.org" <svn-src-head@freebsd.org>, "svn-src-all@freebsd.org" <svn-src-all@freebsd.org>, Alfred Perlstein <alfred@freebsd.org>, "src-committers@freebsd.org" <src-committers@freebsd.org>, John Baldwin <jhb@freebsd.org>
Subject:   Re: svn commit: r275136 - in head/sys: dev/e1000 dev/ixgbe kern sys
Message-ID:  <EB6CB885-C5B2-4D7C-A502-18A4E8F5EF40@mu.org>
In-Reply-To: <547C8CA2.8040305@selasky.org>
References:  <201411262019.sAQKJaw4043557@svn.freebsd.org> <39377603.10OyiSzjWY@ralph.baldwin.cx> <872C180A-6ADD-469F-A801-3728DF134EEC@mu.org> <547C88A9.1070007@selasky.org> <5E1B6CD4-BBA7-4AD0-9982-E981015AF138@mu.org> <547C8A9C.4080603@selasky.org> <F621EBD1-C330-456A-B130-A2F46B5F8355@mu.org> <547C8CA2.8040305@selasky.org>

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> On Dec 1, 2014, at 7:43 AM, Hans Petter Selasky <hps@selasky.org> wrote:
>=20
>> On 12/01/14 16:39, Alfred Perlstein wrote:
>>=20
>>=20
>>>> On Dec 1, 2014, at 7:34 AM, Hans Petter Selasky <hps@selasky.org> wrote=
:
>>>>=20
>>>> On 12/01/14 16:29, Alfred Perlstein wrote:
>>>>=20
>>>>=20
>>>>>> On Dec 1, 2014, at 7:26 AM, Hans Petter Selasky <hps@selasky.org> wro=
te:
>>>>>>=20
>>>>>> On 12/01/14 16:19, Alfred Perlstein wrote:
>>>>>> It makes little sense to have a rw sysctl that only takes effect "som=
e times". This violates POLA at the expense of making code appear cleaner. E=
xpectation is that writable sysctls take
>>>>>=20
>>>>> Hi,
>>>>>=20
>>>>> 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 envirome=
nt, if any. That way you can just skip the TUNABLE_INT_FETCH() stuff!
>>>>=20
>>>> Ok I can probably switch to that.
>>>>=20
>>>> Any objection if I mfc this feature to -stable if it does what I need?
>>>=20
>>> Hi,
>>>=20
>>> 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 definitio=
ns, like static SYSCTLS which have already CTLFLAG_TUN and a TUNABLE fetch s=
tatement, which makes the variable init twice. Just look at the revision his=
tory for "kern/kern_sysctl.c" in 11-current.
>>>=20
>>> --HPS
>>=20
>> One question though... For the global sysctl for all nodes....
>>=20
>> When is the var fetched?  If it's before SI_SUB_CPU it is not useful.
>=20
> Hi,
>=20
> It is quite early, actually:
>=20
> SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_FIRST, sysctl_register_all, 0);
>=20
> In some parts of the machine independent, MI, code you neee to keep the TU=
NABLE_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.=20

Is that ok?



>=20
> --HPS
>=20
>=20
>=20



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