From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <44D98CAB.8090202@garzik.org> Date: Wed, 09 Aug 2006 03:20:11 -0400 From: Jeff Garzik MIME-Version: 1.0 Subject: Re: [RFC][PATCH 8/9] 3c59x driver conversion References: <20060808193447.1396.59301.sendpatchset@lappy> <44D9191E.7080203@garzik.org> <44D977D8.5070306@google.com> <20060808.225537.112622421.davem@davemloft.net> <44D980EB.5010608@garzik.org> <1155107002.23134.40.camel@lappy> In-Reply-To: <1155107002.23134.40.camel@lappy> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Peter Zijlstra Cc: David Miller , phillips@google.com, netdev@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: Peter Zijlstra wrote: > On Wed, 2006-08-09 at 02:30 -0400, Jeff Garzik wrote: >> David Miller wrote: >>> From: Daniel Phillips >>> Date: Tue, 08 Aug 2006 22:51:20 -0700 >>> >>>> Elaborate please. Do you think that all drivers should be updated to >>>> fix the broken blockdev semantics, making NETIF_F_MEMALLOC redundant? >>>> If so, I trust you will help audit for it? >>> I think he's saying that he doesn't think your code is yet a >>> reasonable way to solve the problem, and therefore doesn't belong >>> upstream. >> Pretty much. It is completely non-sensical to add NETIF_F_MEMALLOC, >> when it should be blindingly obvious that every net driver will be >> allocating memory, and every net driver could potentially be used with >> NBD and similar situations. > > Sure, but until every single driver is converted I'd like to warn people > about the fact that their setups is not up to expectations. Iff all > drivers are converted I'll be the forst to submit a patch that removes > the feature flag. A temporary-for-years flag is not a good approach. The flag is not _needed_ for technical reasons, but for supposed user expectation reasons. Rather, just go ahead and convert drivers to netdev_alloc_skb() where people care. If someone suddenly gets a burr up their ass about the sunlance or epic100 driver deadlocking on NBD, then they can convert it or complain loudly themselves. Overall, a good solution needs to be uniform across all net drivers. NETIF_F_MEMALLOC is just _encouraging_ people to be slackers and delay converting other drivers, creating two classes of drivers, the "haves" and the "have nots". Just make a big netdev_alloc_skb() patch that converts most users. netdev_alloc_skb() is a good thing to use, because it builds an association with struct net_device and the allocation. Jeff P.S. Since netdev_alloc_skb() calls skb_reserve(), you need to take that into account. That's a bug in current patches. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org