Date: Mon, 14 Mar 2011 19:43:25 -0700 From: YongHyeon PYUN <pyunyh@gmail.com> To: Vijay Singh <vijju.singh@gmail.com> Cc: freebsd-net@freebsd.org Subject: Re: Jumbo frame support for BGE_ASICREV_BCM5714 Message-ID: <20110315024325.GG1577@michelle.cdnetworks.com> In-Reply-To: <AANLkTimqca%2B72jvWi89LnrP0F4MNdvK7YaG2pTavNiC3@mail.gmail.com> References: <AANLkTimqca%2B72jvWi89LnrP0F4MNdvK7YaG2pTavNiC3@mail.gmail.com>
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On Mon, Mar 14, 2011 at 05:54:29PM -0700, Vijay Singh wrote: > Hi all. I'm working off 7.1. Is there support for jumbo frames > available on bge(4) for BGE_ASICREV_BCM5714? > > regards, > vijay > > PS: my version of the code looks like this: > > case BGE_ASICREV_BCM5714_A0: > case BGE_ASICREV_BCM5780: > case BGE_ASICREV_BCM5714: > sc->bge_flags |= BGE_FLAG_5714_FAMILY /* | BGE_FLAG_JUMBO */; > /* FALLTHRU */ As you know, BCM5714, BCM5715 and BCM5780 use unique jumbo frame scheme that is not compatible with other controllers. All other Broadcom controllers have better jumbo frame scheme. These controllers have one send ring, one standard receive producer ring and one receive return ring. In order to receive jumbo frames on these controllers you have to increase Rx buffer size to hold 9k sized jumbo frame. Two Rx modes(standard Rx BDs and extended Rx BDs) are supported for these controllers. Using extended Rx BDs on BCM5714/BCM5715/BCM5780 reduces the number of Rx BDs to 256 entries which shall reduce the performance. I would use standard Rx BDs to hold 512 entries for RX buffers. I think I received jumbo frame support request for these controllers in past. At that time I had no interests on implementing it due to severe implementation differences. What is your main reason to use jumbo frame on this controller? What is your expectation on performance numbers? I guess no other OSes support jumbo frame on this controller.
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