From patchwork Wed Apr 13 20:24:03 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Miller X-Patchwork-Id: 91105 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44E32B6F35 for ; Thu, 14 Apr 2011 06:24:44 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757594Ab1DMUYj (ORCPT ); Wed, 13 Apr 2011 16:24:39 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:50274 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757492Ab1DMUYj (ORCPT ); Wed, 13 Apr 2011 16:24:39 -0400 Received: from localhost (localhost [127.0.0.1]) by sunset.davemloft.net (Postfix) with ESMTP id AF28624C088; Wed, 13 Apr 2011 13:24:03 -0700 (PDT) Date: Wed, 13 Apr 2011 13:24:03 -0700 (PDT) Message-Id: <20110413.132403.179942105.davem@davemloft.net> To: dimetrios@gmail.com Cc: eric.dumazet@gmail.com, shemminger@linux-foundation.org, netdev@vger.kernel.org Subject: Re: [Bug 32772] New: PROBLEM: kernel BUG at net/ipv4/inetpeer.c:386 From: David Miller In-Reply-To: References: <20110406.111649.193697123.davem@davemloft.net> X-Mailer: Mew version 6.3 on Emacs 23.1 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Dmitry Novikov Date: Wed, 13 Apr 2011 23:14:03 +0300 > Crash again after 7 days of uptime. slub_nomerge is set Looks like too deep stack, try this patch which is in net-2.6: -------------------- inetpeer: reduce stack usage On 64bit arches, we use 752 bytes of stack when cleanup_once() is called from inet_getpeer(). Lets share the avl stack to save ~376 bytes. Before patch : # objdump -d net/ipv4/inetpeer.o | scripts/checkstack.pl 0x000006c3 unlink_from_pool [inetpeer.o]: 376 0x00000721 unlink_from_pool [inetpeer.o]: 376 0x00000cb1 inet_getpeer [inetpeer.o]: 376 0x00000e6d inet_getpeer [inetpeer.o]: 376 0x0004 inet_initpeers [inetpeer.o]: 112 # size net/ipv4/inetpeer.o text data bss dec hex filename 5320 432 21 5773 168d net/ipv4/inetpeer.o After patch : objdump -d net/ipv4/inetpeer.o | scripts/checkstack.pl 0x00000c11 inet_getpeer [inetpeer.o]: 376 0x00000dcd inet_getpeer [inetpeer.o]: 376 0x00000ab9 peer_check_expire [inetpeer.o]: 328 0x00000b7f peer_check_expire [inetpeer.o]: 328 0x0004 inet_initpeers [inetpeer.o]: 112 # size net/ipv4/inetpeer.o text data bss dec hex filename 5163 432 21 5616 15f0 net/ipv4/inetpeer.o Signed-off-by: Eric Dumazet Cc: Scot Doyle Cc: Stephen Hemminger Cc: Hiroaki SHIMODA Reviewed-by: Hiroaki SHIMODA Signed-off-by: David S. Miller --- net/ipv4/inetpeer.c | 13 +++++++------ 1 files changed, 7 insertions(+), 6 deletions(-) diff --git a/net/ipv4/inetpeer.c b/net/ipv4/inetpeer.c index dd1b20e..9df4e63 100644 --- a/net/ipv4/inetpeer.c +++ b/net/ipv4/inetpeer.c @@ -354,7 +354,8 @@ static void inetpeer_free_rcu(struct rcu_head *head) } /* May be called with local BH enabled. */ -static void unlink_from_pool(struct inet_peer *p, struct inet_peer_base *base) +static void unlink_from_pool(struct inet_peer *p, struct inet_peer_base *base, + struct inet_peer __rcu **stack[PEER_MAXDEPTH]) { int do_free; @@ -368,7 +369,6 @@ static void unlink_from_pool(struct inet_peer *p, struct inet_peer_base *base) * We use refcnt=-1 to alert lockless readers this entry is deleted. */ if (atomic_cmpxchg(&p->refcnt, 1, -1) == 1) { - struct inet_peer __rcu **stack[PEER_MAXDEPTH]; struct inet_peer __rcu ***stackptr, ***delp; if (lookup(&p->daddr, stack, base) != p) BUG(); @@ -422,7 +422,7 @@ static struct inet_peer_base *peer_to_base(struct inet_peer *p) } /* May be called with local BH enabled. */ -static int cleanup_once(unsigned long ttl) +static int cleanup_once(unsigned long ttl, struct inet_peer __rcu **stack[PEER_MAXDEPTH]) { struct inet_peer *p = NULL; @@ -454,7 +454,7 @@ static int cleanup_once(unsigned long ttl) * happen because of entry limits in route cache. */ return -1; - unlink_from_pool(p, peer_to_base(p)); + unlink_from_pool(p, peer_to_base(p), stack); return 0; } @@ -524,7 +524,7 @@ struct inet_peer *inet_getpeer(struct inetpeer_addr *daddr, int create) if (base->total >= inet_peer_threshold) /* Remove one less-recently-used entry. */ - cleanup_once(0); + cleanup_once(0, stack); return p; } @@ -540,6 +540,7 @@ static void peer_check_expire(unsigned long dummy) { unsigned long now = jiffies; int ttl, total; + struct inet_peer __rcu **stack[PEER_MAXDEPTH]; total = compute_total(); if (total >= inet_peer_threshold) @@ -548,7 +549,7 @@ static void peer_check_expire(unsigned long dummy) ttl = inet_peer_maxttl - (inet_peer_maxttl - inet_peer_minttl) / HZ * total / inet_peer_threshold * HZ; - while (!cleanup_once(ttl)) { + while (!cleanup_once(ttl, stack)) { if (jiffies != now) break; }