Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751815Ab3JGXyO (ORCPT ); Mon, 7 Oct 2013 19:54:14 -0400 Received: from mail-yh0-f50.google.com ([209.85.213.50]:59154 "EHLO mail-yh0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751613Ab3JGXyN (ORCPT ); Mon, 7 Oct 2013 19:54:13 -0400 Message-ID: <1381190047.12191.32.camel@edumazet-glaptop.roam.corp.google.com> Subject: Re: [PATCH 4/4] [RFC] ipv6: Fix for possible ipv6 seqlock deadlock From: Eric Dumazet To: John Stultz Cc: LKML , Mathieu Desnoyers , Steven Rostedt , Peter Zijlstra , Ingo Molnar , Thomas Gleixner , "David S. Miller" , Alexey Kuznetsov , James Morris , Hideaki YOSHIFUJI , Patrick McHardy Date: Mon, 07 Oct 2013 16:54:07 -0700 In-Reply-To: <1381186321-4906-5-git-send-email-john.stultz@linaro.org> References: <1381186321-4906-1-git-send-email-john.stultz@linaro.org> <1381186321-4906-5-git-send-email-john.stultz@linaro.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1958 Lines: 55 On Mon, 2013-10-07 at 15:52 -0700, John Stultz wrote: > While enabling lockdep on seqlocks, I ran across the warning below > caused by the ipv6 stats being updated in both irq and non-irq context. You mean a lockdep warning on a seqcount in this context, right ? > > This patch changes from IP6_INC_STATS_BH to IP6_INC_STATS (suggested > by Eric Dumazet) to resolve this problem. ... > Cc: Eric Dumazet > Cc: Mathieu Desnoyers > Cc: Steven Rostedt > Cc: Peter Zijlstra > Cc: Ingo Molnar > Cc: Thomas Gleixner > Cc: "David S. Miller" > Cc: Alexey Kuznetsov > Cc: James Morris > Cc: Hideaki YOSHIFUJI > Cc: Patrick McHardy > Signed-off-by: John Stultz > --- > net/ipv6/ip6_output.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c > index 3a692d5..7e63c1e 100644 > --- a/net/ipv6/ip6_output.c > +++ b/net/ipv6/ip6_output.c > @@ -909,7 +909,7 @@ static int ip6_dst_lookup_tail(struct sock *sk, > > out_err_release: > if (err == -ENETUNREACH) > - IP6_INC_STATS_BH(net, NULL, IPSTATS_MIB_OUTNOROUTES); > + IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES); > dst_release(*dst); > *dst = NULL; > return err; This one is certainly a bug fix, David please consider adding it to your net tree Bug added in commit ca46f9c834913f ("[IPv6] SNMP: Increment OutNoRoutes when connecting to unreachable network") Acked-by: Eric Dumazet -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/