Date: Mon, 17 Sep 2012 16:22:11 -0400 From: John Baldwin <jhb@freebsd.org> To: Jack Vogel <jfvogel@gmail.com> Cc: freebsd-net@freebsd.org, Adrian Chadd <adrian@freebsd.org>, Ryan Stone <rysto32@gmail.com> Subject: Re: What's the latest on fixing IFF_DRV_OACTIVE/if_start/etc? Message-ID: <201209171622.11157.jhb@freebsd.org> In-Reply-To: <CAFOYbcmt93px4poAmLgv6F288CDP_mPcejU8Mw5-h3h-A7bKUA@mail.gmail.com> References: <CAFMmRNzkwbQpUZ3OOoMKVdrz=dePc5fkeX3m-5vXtiWJ7qXwVA@mail.gmail.com> <201209171503.12517.jhb@freebsd.org> <CAFOYbcmt93px4poAmLgv6F288CDP_mPcejU8Mw5-h3h-A7bKUA@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Monday, September 17, 2012 4:00:04 pm Jack Vogel wrote: > So, you mean having them create their own buf ring I assume? Would be easy > enough to hack some code and try it if someone is so inclined? No, that would be backwards (back to giving them a queue). Adrian's suggestion is to provide a mechanism so that the "real" interface (e.g. emX) can call back into the psuedo-interfaces on top of it (vlanX or bridgeX) when a TX completion interrupt fires so that the pseudo-interface would know to restart transmission. However, I think this is generally not ideal. I don't think we want an additional queue of pending packets in things like if_bridge(4) and vlan(4). If the underlying physical interface(s) are full, the packet should just get dropped rather than queued. Using if_transmit directly will do that while avoiding overhead. Also, making the callback work would also be a bit ungainly. -- John Baldwin
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201209171622.11157.jhb>