From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [patch 4/10] s390: network driver. Date: Mon, 20 Dec 2004 20:19:42 -0500 Message-ID: <41C77A2E.3090000@pobox.com> References: <1103484552.1046.155.camel@jzny.localdomain> <41C600D7.70005@tpack.net> <1103497516.1046.231.camel@jzny.localdomain> <41C612BC.5070909@tpack.net> <1103551830.1047.316.camel@jzny.localdomain> <41C71FFD.7090308@pobox.com> <41C76AA0.7020800@tpack.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: hadi@cyberus.ca, Thomas Spatzier , "David S. Miller" , Hasso Tepper , Herbert Xu , netdev@oss.sgi.com, Paul Jakma Return-path: To: Tommy Christensen In-Reply-To: <41C76AA0.7020800@tpack.net> Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org Tommy Christensen wrote: > Jeff Garzik wrote: > >> I haven't heard anything to convince me that the same change should be >> deployed across NNN drivers. The drivers already signal the net core >> that the link is down; to me, that implies there should be code in >> _one_ place that handles this condition, not NNN places. > > > AFAICS only a handful of (newer) drivers call netif_stop_queue() directly. > Others may do this indirectly if the MAC stops taking packets from the > DMA ringbuffer. At least some MAC's/drivers certainly don't. Incorrect. Use of netif_stop_queue() is -required- to signal that the hardware cannot accept any more skbs from the system. Far more than a "handful" and required for all but a few very strange drivers. > OK, another view on this: isn't is problematic to have skb's stuck in > the network stack "indefinitely" ? > They hold references to a dst_entry and a sock (and probably more). > So how about this for the FAQ: > Q: Why can't I unload the af_packet module? > A: Ohh, you'll have to plug in the darn cable to eth0 first! > *Please* tell me, I've got this all wrong. You've got this all wrong. Jeff