From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 73019C433E1 for ; Wed, 26 Aug 2020 18:52:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4BA022078A for ; Wed, 26 Aug 2020 18:52:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726910AbgHZSwg (ORCPT ); Wed, 26 Aug 2020 14:52:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43660 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726809AbgHZSwd (ORCPT ); Wed, 26 Aug 2020 14:52:33 -0400 Received: from ganesha.gnumonks.org (unknown [IPv6:2001:780:45:1d:225:90ff:fe52:c662]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4E3B1C061574 for ; Wed, 26 Aug 2020 11:52:31 -0700 (PDT) Received: from uucp by ganesha.gnumonks.org with local-bsmtp (Exim 4.89) (envelope-from ) id 1kB0Wy-0006aR-Qy; Wed, 26 Aug 2020 20:52:20 +0200 Received: from laforge by localhost.localdomain with local (Exim 4.94) (envelope-from ) id 1kB0Wg-000Xwy-FF; Wed, 26 Aug 2020 20:52:02 +0200 Date: Wed, 26 Aug 2020 20:52:02 +0200 From: Harald Welte To: Nicolas Dichtel Cc: netdev@vger.kernel.org, osmocom-net-gprs@lists.osmocom.org, Gabriel Ganne , kuba@kernel.org, davem@davemloft.net, pablo@netfilter.org Subject: Re: [PATCH net-next v2] gtp: add notification mechanism Message-ID: <20200826185202.GZ3739@nataraja> References: <20200825143556.23766-1-nicolas.dichtel@6wind.com> <20200825155715.24006-1-nicolas.dichtel@6wind.com> <20200825170109.GH3822842@nataraja> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hi Nicolas, On Wed, Aug 26, 2020 at 09:47:54AM +0200, Nicolas Dichtel wrote: > > Sending (unsolicited) notifications about all of those seems quite heavyweight to me. > > There is no 'unsolicited' notifications with this patch. Notifications are sent > only if a userspace application has subscribed to the gtp mcast group. > ip routes or conntrack entries are notified in the same way and there could a > lot of them also (more than 100k conntrack entries for example). Ok, thanks for reminding me of that. However, even if those events are not sent/multicasted, it still looks like the proposed patch is unconditionally allocating a netlink message and filling it with information about the PDP. That alone looks like adding significant overhead to every user - even the majority of current use cases where nobody is listening/subscribing to that multicast group. Wouldn't it make sense to only allocate + fill those messages if we actually knew a subscriber existed? -- - Harald Welte http://laforge.gnumonks.org/ ============================================================================ "Privacy in residential applications is a desirable marketing option." (ETSI EN 300 175-7 Ch. A6)