From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Borkmann Subject: Re: [PATCH] net: do not use rcu in rtnl_dump_ifinfo() Date: Fri, 27 Feb 2015 18:19:27 +0100 Message-ID: <54F0A71F.3040808@iogearbox.net> References: <1425018776-14725-1-git-send-email-xiyou.wangcong@gmail.com> <1425024069.5130.10.camel@edumazet-glaptop2.roam.corp.google.com> <54F09A95.8000507@6wind.com> <1425056838.5130.27.camel@edumazet-glaptop2.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Cong Wang , netdev@vger.kernel.org To: Eric Dumazet , nicolas.dichtel@6wind.com, David Miller Return-path: Received: from www62.your-server.de ([213.133.104.62]:59144 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752069AbbB0RTc (ORCPT ); Fri, 27 Feb 2015 12:19:32 -0500 In-Reply-To: <1425056838.5130.27.camel@edumazet-glaptop2.roam.corp.google.com> Sender: netdev-owner@vger.kernel.org List-ID: On 02/27/2015 06:07 PM, Eric Dumazet wrote: > From: Eric Dumazet > > We did a failed attempt in the past to only use rcu in rtnl dump > operations (commit e67f88dd12f6 "net: dont hold rtnl mutex during > netlink dump callbacks") > > Now that dumps are holding RTNL anyway, there is no need to also > use rcu locking, as it forbids any scheduling ability, like > GFP_KERNEL allocations that controlling path should use instead > of GFP_ATOMIC whenever possible. > > This should fix following splat Cong Wang reported : > > =============================== [ Btw, I think patchwork has an issue with above line when fetching the mbox : it thinks commit description ends here. :( Prefixing with a space char should help to not get it lost. ]