From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [RFC PATCH 0/2] remove netpoll rx support Date: Tue, 11 Mar 2014 16:09:31 -0400 (EDT) Message-ID: <20140311.160931.1395978386605601765.davem@davemloft.net> References: <87a9cxf7mp.fsf_-_@xmission.com> <20140311.124907.1180556684992271103.davem@davemloft.net> <87wqg0cy9d.fsf@xmission.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: eric.dumazet@gmail.com, netdev@vger.kernel.org, xiyou.wangcong@gmail.com, mpm@selenic.com, satyam.sharma@gmail.com To: ebiederm@xmission.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:58193 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755649AbaCKUJf (ORCPT ); Tue, 11 Mar 2014 16:09:35 -0400 In-Reply-To: <87wqg0cy9d.fsf@xmission.com> Sender: netdev-owner@vger.kernel.org List-ID: From: ebiederm@xmission.com (Eric W. Biederman) Date: Tue, 11 Mar 2014 12:48:30 -0700 > David Miller writes: > >> From: ebiederm@xmission.com (Eric W. Biederman) >> Date: Tue, 11 Mar 2014 01:43:10 -0700 >> >>> Furthermore netpoll by it's design depends on the ability to receive >>> packets in netpoll_poll_dev. It is a capability I don't think we have >>> ever used in the mainline kernel but it is a capability that is there >>> deliberately. Which means if we want netpoll to not mess with the rx >>> path we need to change netpoll. >> >> This breaks kdump, and any other users of netpoll_rx() et al. > > It does not break kdump. (kdump starts a new kernel to do it's work). > > It does break the ancient lkcd netdump that was never merged, and has > been abandoned (to the best of my knowledge). crash dumps proved > entirely too fragile to perform from a broken kernel. I feel like I've mixed this up in the past, multiple times, thanks for the sanity check. >> Make the zero budget depend upon us being invoked from hardware >> irq context, or something like that. > > Good enough. I will respin my driver patches based on the assumption > that netpoll will be changed in this way. There are no dependencies > for the drivers, I just need to remove my rx path changes. > > We can have the conversation about how to change netpoll in parallel. Sounds great.