From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753992AbdBEUMG (ORCPT + 2 others); Sun, 5 Feb 2017 15:12:06 -0500 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:27808 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752266AbdBETYM (ORCPT ); Sun, 5 Feb 2017 14:24:12 -0500 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: Konstantin Khlebnikov , "David S . Miller" , Willy Tarreau Subject: [PATCH 3.10 237/319] net: ratelimit warnings about dst entry refcount underflow or overflow Date: Sun, 5 Feb 2017 20:20:59 +0100 Message-Id: <1486322541-8206-138-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1486322541-8206-1-git-send-email-w@1wt.eu> References: <1486322541-8206-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: From: Konstantin Khlebnikov commit 8bf4ada2e21378816b28205427ee6b0e1ca4c5f1 upstream. Kernel generates a lot of warnings when dst entry reference counter overflows and becomes negative. That bug was seen several times at machines with outdated 3.10.y kernels. Most like it's already fixed in upstream. Anyway that flood completely kills machine and makes further debugging impossible. Signed-off-by: Konstantin Khlebnikov Signed-off-by: David S. Miller Signed-off-by: Willy Tarreau --- net/core/dst.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/core/dst.c b/net/core/dst.c index 1bf6842..582b861 100644 --- a/net/core/dst.c +++ b/net/core/dst.c @@ -283,7 +283,9 @@ void dst_release(struct dst_entry *dst) unsigned short nocache = dst->flags & DST_NOCACHE; newrefcnt = atomic_dec_return(&dst->__refcnt); - WARN_ON(newrefcnt < 0); + if (unlikely(newrefcnt < 0)) + net_warn_ratelimited("%s: dst:%p refcnt:%d\n", + __func__, dst, newrefcnt); if (!newrefcnt && unlikely(nocache)) call_rcu(&dst->rcu_head, dst_destroy_rcu); } -- 2.8.0.rc2.1.gbe9624a