From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH 18/29] netfilter: notify about NF_QUEUE vs emergency skbs From: Peter Zijlstra In-Reply-To: <45E06A86.2060408@trash.net> References: <20070221144304.512721000@taijtu.programming.kicks-ass.net> <20070221144843.299254000@taijtu.programming.kicks-ass.net> <45E05954.8050204@trash.net> <1172332010.28579.6.camel@lappy> <45E064FF.8010000@trash.net> <1172333937.6374.47.camel@twins> <45E06A86.2060408@trash.net> Content-Type: text/plain Date: Sat, 24 Feb 2007 17:55:49 +0100 Message-Id: <1172336149.28579.11.camel@lappy> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Patrick McHardy Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, Trond Myklebust , Thomas Graf , David Miller List-ID: On Sat, 2007-02-24 at 17:40 +0100, Patrick McHardy wrote: > Peter Zijlstra wrote: > > On Sat, 2007-02-24 at 17:17 +0100, Patrick McHardy wrote: > > > > > >>I don't really see why > >>queueing is special though, dropping the packets in the ruleset > >>will break things just as well, as will routing them to a blackhole. > >>I guess the user just needs to be smart enough not to do this. > > > > > > Its user-space and no emergency packet may rely on user-space because it > > most likely is needed to maintain user-space. > > I believe I might have misunderstood the intention of this patch. > > Assuming the user is smart enough not to queue packets destined > to a SOCK_VMIO socket, are you worried about unrelated packets > allocated from the emergency reserve not getting freed fast > enough because they're sitting in a queue? In that case simply > dropping the packets would be fine I guess. OK, that sounds good. I shall make NF_QUEUE a black hole for emergency packets. Alas, that leaves no way to warn a user about a SOCK_VMIO bound packet treated this way, since, as you said, that is unknown at this point in the chain. Thanks, Peter -- 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