From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from shards.monkeyblade.net ([184.105.139.130]:59806 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751814AbeCVTOR (ORCPT ); Thu, 22 Mar 2018 15:14:17 -0400 Date: Thu, 22 Mar 2018 15:14:14 -0400 (EDT) Message-Id: <20180322.151414.425331877216053698.davem@davemloft.net> To: ktkhai@virtuozzo.com Cc: yoshfuji@linux-ipv6.org, edumazet@google.com, yanhaishuang@cmss.chinamobile.com, nikolay@cumulusnetworks.com, yotamg@mellanox.com, soheil@google.com, avagin@virtuozzo.com, nicolas.dichtel@6wind.com, ebiederm@xmission.com, fw@strlen.de, roman.kapl@sysgo.com, netdev@vger.kernel.org, xiyou.wangcong@gmail.com, dvyukov@google.com, andreyknvl@google.com, lkp@intel.com Subject: Re: [PATCH net-next v3 0/5] Rework ip_ra_chain protection From: David Miller In-Reply-To: <152171176936.18202.11912079579606814167.stgit@localhost.localdomain> References: <152171176936.18202.11912079579606814167.stgit@localhost.localdomain> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org List-ID: From: Kirill Tkhai Date: Thu, 22 Mar 2018 12:44:46 +0300 > Commit 1215e51edad1 "ipv4: fix a deadlock in ip_ra_control" > made rtnl_lock() be used in raw_close(). This function is called > on every RAW socket destruction, so that rtnl_mutex is taken > every time. This scales very sadly. I observe cleanup_net() > spending a lot of time in rtnl_lock() and raw_close() is one > of the biggest rtnl user (since we have percpu net->ipv4.icmp_sk). > > This patchset reworks the locking: reverts the problem commit > and its descendant, and introduces rtnl-independent locking. > This may have a continuation, and someone may work on killing > rtnl_lock() in mrtsock_destruct() in the future. > > Thanks, > Kirill > > --- > v3: Change patches order: [2/5] and [3/5]. > v2: Fix sparse warning [4/5], as reported by kbuild test robot. This looks a lot better, series applied, thank you.