Date: Wed, 29 Mar 2006 09:20:29 -0500 From: "Bosko Milekic" <bosko.milekic@gmail.com> To: "=?ISO-8859-1?Q?Dag-Erling_Sm=F8rgrav?=" <des@des.no> Cc: Chris <chrcoluk@gmail.com>, "Conrad J. Sabatier" <conrads@cox.net>, freebsd-stable@freebsd.org Subject: Re: nmbclusters Message-ID: <bbebbd3d0603290620g4126dccekf5e48837d23513d2@mail.gmail.com> In-Reply-To: <861wwlcsnj.fsf@xps.des.no> References: <3aaaa3a0603281134sd0d4e16x@mail.gmail.com> <20060329030459.40be9cb2.conrads@cox.net> <861wwlcsnj.fsf@xps.des.no>
next in thread | previous in thread | raw e-mail | index | archive | help
It's always only been boot-time tunable (well, "always" is of course relative to my time with FreeBSD -- Dag-Erling has been around longer and therefore recounts its more comprehensive history). In 6.0-CURRENT there was an intention to make it sysctl (runtime) tunable, as it finally became at least theoretically possible to do so. I have recently seen a patch floating around from Paul Saab (ps@) who has finally made it runtime tunable -- at least enough so that it can be _increased_. Not sure if he has committed it, yet. Note that _decreasing_ nmbclusters at run-time will probably never be possible -- implementing is too difficult for what it would be worth. Cheers, Bosko On 3/29/06, Dag-Erling Smørgrav <des@des.no> wrote: > "Conrad J. Sabatier" <conrads@cox.net> writes: > > Chris <chrcoluk@gmail.com> wrote: > > > so [kern.ipc.nmbclusters] has no affect, has this become a read only > > > tunable again only settable in loader.conf? > > To the best of my knowledge, this has *always* been a loader tunable, > > not configurable on-the-fly. > > kern.ipc.nmbclusters is normally computed at boot time. A compile- > time option to override it was introduced in 2.0-CURRENT. At that > time, it was defined in param.c. A read-only sysctl was introduced in > 3.0-CURRENT. It moved from param.c to uipc_mbuf.c in 4.0-CURRENT, > then to subr_mbuf.c when mballoc was introduced in 5.0-CURRENT; became > a tunable at some point after that; then moved again to kern_mbuf.c > when mballoc was replaced with mbuma in 6.0-CURRENT. That is the > point where it became read-write, for no good reason that I can see; > setting it at runtime has no effect, because the size of the mbuf zone > is determined at boot time. Perhaps Bosko (who wrote both mballoc and > mbuma, IIRC) knows. > > DES > -- > Dag-Erling Smørgrav - des@des.no > -- Bosko Milekic <bosko.milekic@gmail.com> To see all the content I generate on the web, check out my Peoplefeeds profile at: http://peoplefeeds.com/bosko
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?bbebbd3d0603290620g4126dccekf5e48837d23513d2>