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: > >> On 12/01/14 16:39, Alfred Perlstein wrote: >> >> >>>> On Dec 1, 2014, at 7:34 AM, Hans Petter Selasky <hps@selasky.org> wrote: >>>> >>>> On 12/01/14 16:29, Alfred Perlstein wrote: >>>> >>>> >>>>>> On Dec 1, 2014, at 7:26 AM, Hans Petter Selasky <hps@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 > > >help
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