From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?B?UMOhZHJhaWcgQnJhZHk=?= Subject: Re: route/max_size sysctl in ipv4 Date: Tue, 06 Jan 2015 12:41:51 +0000 Message-ID: <54ABD80F.7070602@draigBrady.com> References: <20150105.193614.1827024424476781168.davem@davemloft.net> <20150105.195128.794605376092864881.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "netdev@vger.kernel.org" To: Ani Sinha , David Miller Return-path: Received: from mail2.vodafone.ie ([213.233.128.44]:21335 "EHLO mail2.vodafone.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754955AbbAFMmB (ORCPT ); Tue, 6 Jan 2015 07:42:01 -0500 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On 06/01/15 00:56, Ani Sinha wrote: > On Mon, Jan 5, 2015 at 4:51 PM, David Miller wr= ote: >> From: Ani Sinha >> Date: Mon, 5 Jan 2015 16:43:30 -0800 >> >>> On Mon, Jan 5, 2015 at 4:36 PM, David Miller = wrote: >>>> From: Ani Sinha >>>> Date: Mon, 5 Jan 2015 15:48:11 -0800 >>>> >>>>> I am looking at the code and it looks like since the route cache = for >>>>> ipv4 was removed from the kernel, this sysctl parameter no longer >>>>> serves the same purpose. It does not look like it is even used in= the >>>>> ipv4/route.c module. Is there an equivalent sysctl parameter limi= ting >>>>> the number of route entries in the kernel? Or is there now no >>>>> mechanism to limit the number of route entries? >>>> >>>> There is nothing to limit, since the cache was removed. >>> >>> Shouldn't the documentation be updated to reflect that? Also what's >>> the point of having a dummy variable that does nothing? Should we n= ot >>> simply remove it? >> >> There is nothing to update, the behavior is completely transparent. >> Absolutely no cache entries exist, therefore the limit cannot be >> reached. >=20 > I disagree. You are advertising a feature in an official documentatio= n > that simply does not exist for ipv4. This is very confusing. If I did > not dig into the code, I wouldn't know that this particular knob is a > noop since the time the route cache was removed. You can't change APIs with impunity. >> The sysctl is kept so that scripts reading it don't suddenly stop >> working. We can't just remove sysctl values. Perhaps /proc/sys/net/ipv4/route/max_size should always return 0 when r= ead, and discard written values? thanks, P=C3=A1draig