Date: Sat, 30 Sep 2006 01:30:23 +0200 From: Andre Oppermann <andre@freebsd.org> To: Andre Oppermann <andre@freebsd.org>, freebsd-net@freebsd.org, Randall Stewart <rrs@cisco.com>, freebsd-current@freebsd.org, Mike Silbersack <silby@silby.com>, gallatin@cs.duke.edu Subject: Re: Much improved sosend_*() functions Message-ID: <451DAC8F.7030309@freebsd.org> In-Reply-To: <20060929231007.GS80527@funkthat.com> References: <451C4850.5030302@freebsd.org> <Pine.BSF.4.58.0609281928020.20971@niwun.pair.com> <451D884F.1030807@cisco.com> <20060929213722.GR80527@funkthat.com> <451D973C.8070004@freebsd.org> <20060929231007.GS80527@funkthat.com>
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John-Mark Gurney wrote: > Andre Oppermann wrote this message on Fri, Sep 29, 2006 at 23:59 +0200: >> Just don't overengineer the stuff. Mbufs are only used temporarily and >> a bit theoretical waste is not much a problem (so far at least). > > Well, I beg to differ... most gige cards grab mbuf+cluster for every > single ring buffer they have.. which is usually 512... so every gige > interface for the most part consumes 1meg of memory that is not > reusable... because if we run out of mbuf+clusters to replace in the > receive ring, we will not tap into the 1meg of mbuf+clusters available > to us... so, if you have a quad gige, that's 4megs wasted, plus w/ the > fact that we could only use ~65% of that memory, that's a lot of memory > wasted... The problem is the network cards again. Only a few allow different rx rings to be used (for example bge(4)) where you can have multiple mbuf (+cluster) sizes and the card choses the smallest fit at receive time. > Yeh, everyone says you have gigs of memory, but do we really want to > be known as the wasteful OS? -- Andre
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