From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,T_DKIMWL_WL_HIGH,UNPARSEABLE_RELAY autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2A77DC43219 for ; Thu, 2 May 2019 09:53:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ECFEC2075E for ; Thu, 2 May 2019 09:53:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="a4Nl+Wzq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726302AbfEBJxy (ORCPT ); Thu, 2 May 2019 05:53:54 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:35614 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726127AbfEBJxy (ORCPT ); Thu, 2 May 2019 05:53:54 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x429o76m023566; Thu, 2 May 2019 09:53:43 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : in-reply-to : message-id : references : mime-version : content-type; s=corp-2018-07-02; bh=jCOv2IB+99FgoGG+HZuRwDd5uyXuUrVxmQE1oOOcEy4=; b=a4Nl+WzqsCUdG6IBoiak1okiUK/TtuCkwY/hsT4whIfLs9swtJyn+NzKlGMTwrhvnrOm z/3lmsKTbrNYl+KvaOJP0E13nhmcjdCsI6ajxaOwQlh08ZwRbgdfWD5iAUKylSjCBXVz 1+mCdlLymwJ4oMVjXci+nqA/E/UPvowxGh/sXUm2FAo0DkLKUbOWng2xGigBlkkTrIet 4k5D6Pxo1PJ96djp6prR3MJcFwBJVYhBGsx8T8gS2g6dFeQRh7pc7oXMYAk+Hx6WXkLb ZOKt2T1r0nl43QLysjO/0dO9GHvDfclQG/Icy2M7LqKrUQ6Wv9BdwzKUGoPPL46ralMf jg== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2130.oracle.com with ESMTP id 2s6xhyffj8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 02 May 2019 09:53:43 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x429rfcf137157; Thu, 2 May 2019 09:53:43 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3030.oracle.com with ESMTP id 2s7p89p2j0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 02 May 2019 09:53:43 +0000 Received: from abhmp0017.oracle.com (abhmp0017.oracle.com [141.146.116.23]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x429rffp032244; Thu, 2 May 2019 09:53:41 GMT Received: from dhcp-10-175-160-224.vpn.oracle.com (/10.175.160.224) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 02 May 2019 02:53:41 -0700 Date: Thu, 2 May 2019 10:53:34 +0100 (BST) From: Alan Maguire X-X-Sender: alan@dhcp-10-175-160-224.vpn.oracle.com To: David Ahern cc: davem@davemloft.net, netdev@vger.kernel.org, ian.kumlien@gmail.com, alan.maguire@oracle.com, David Ahern Subject: Re: [PATCH net] neighbor: Reset gc_entries counter if new entry is released before insert In-Reply-To: <20190502010834.25519-1-dsahern@kernel.org> Message-ID: References: <20190502010834.25519-1-dsahern@kernel.org> User-Agent: Alpine 2.20 (LRH 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9244 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=3 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905020074 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9244 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=3 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905020074 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, 1 May 2019, David Ahern wrote: > From: David Ahern > > Ian and Alan both reported seeing overflows after upgrades to 5.x kernels: > neighbour: arp_cache: neighbor table overflow! > > Alan's mpls script helped get to the bottom of this bug. When a new entry > is created the gc_entries counter is bumped in neigh_alloc to check if a > new one is allowed to be created. ___neigh_create then searches for an > existing entry before inserting the just allocated one. If an entry > already exists, the new one is dropped in favor of the existing one. In > this case the cleanup path needs to drop the gc_entries counter. There > is no memory leak, only a counter leak. > > Fixes: 58956317c8d ("neighbor: Improve garbage collection") > Reported-by: Ian Kumlien > Reported-by: Alan Maguire > Signed-off-by: David Ahern Tested-by: Alan Maguire > --- > net/core/neighbour.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/net/core/neighbour.c b/net/core/neighbour.c > index 30f6fd8f68e0..aff051e5521d 100644 > --- a/net/core/neighbour.c > +++ b/net/core/neighbour.c > @@ -663,6 +663,8 @@ static struct neighbour *___neigh_create(struct neigh_table *tbl, > out_tbl_unlock: > write_unlock_bh(&tbl->lock); > out_neigh_release: > + if (!exempt_from_gc) > + atomic_dec(&tbl->gc_entries); > neigh_release(n); > goto out; > } > -- > 2.11.0 > >