From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Frederic Sowa Subject: Re: [PATCH] inet: further fixes of possible seqlock deadlocks Date: Thu, 28 Nov 2013 23:19:26 +0100 Message-ID: <20131128221926.GG24171@order.stressinduktion.org> References: <13025162.118881385612276530.JavaMail.weblogic@epv6ml01> <1385659390.5352.20.camel@edumazet-glaptop2.roam.corp.google.com> <1385661082.5352.34.camel@edumazet-glaptop2.roam.corp.google.com> <20131128192231.GE24171@order.stressinduktion.org> <1385672502.5352.38.camel@edumazet-glaptop2.roam.corp.google.com> <20131128212700.GF24171@order.stressinduktion.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 To: Eric Dumazet , jongman.heo@samsung.com, David Miller , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" Return-path: Received: from order.stressinduktion.org ([87.106.68.36]:45222 "EHLO order.stressinduktion.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751015Ab3K1WT1 (ORCPT ); Thu, 28 Nov 2013 17:19:27 -0500 Content-Disposition: inline In-Reply-To: <20131128212700.GF24171@order.stressinduktion.org> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Nov 28, 2013 at 10:27:00PM +0100, Hannes Frederic Sowa wrote: > > > @@ -1524,8 +1524,8 @@ int ip6_push_pending_frames(struct sock *sk) > > > if (proto == IPPROTO_ICMPV6) { > > > struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); > > > > > > - ICMP6MSGOUT_INC_STATS_BH(net, idev, icmp6_hdr(skb)->icmp6_type); > > > - ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTMSGS); > > > + ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type); > > > + ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); > > > > I am not sure we use a seqlock for ICMP stats. > > > > seqlocks were used for 64bit IP stats > > True, atomic longs get used here in both cases. I don't really understand why we distinguish between _BH and plain ICMP stat calls then. The non-_BH versions deactivate interrupts when updating the per-cpu counter.